Alejandro Mitrani
Universidad Nacional Autónoma de México, Physics, Faculty Member
Research Interests:
Alegoría de la construcción and Alegoría del trabajo were the first mural paintings commissioned to Saturnino Herrán (1887-1918), and they occupied a significant place in one of the most important schools in Mexico. The non-invasive... more
Alegoría de la construcción and Alegoría del trabajo were the first mural paintings commissioned to Saturnino Herrán (1887-1918), and they occupied a significant place in one of the most important schools in Mexico. The non-invasive methodology employed included different documentation phases and in situ multi-technique analyses. Hyperspectral imaging and digital radiography were used for a general characterization of the materials and were complemented with localized analyses by portable microscopy, and XRF and FORS spectroscopies. A complete identification of the original and the restoration palettes was achieved. Results from this work allowed us to understand the production context, painting technique, and conservation state, thus providing insights for the proper conservation of these murals, while also unveiling a new perception of the artist and his historical place among the muralist movement.
Research Interests:
Portable X-ray fluorescence (pXRF) geochemical analysis on obsidian from five Formative period (1200 BCE to AC 100) sites from Tlaxcala, Mexico, has revealed that most of the material had similar values to those found in the closest... more
Portable X-ray fluorescence (pXRF) geochemical analysis on obsidian from five Formative period (1200 BCE to AC 100) sites from Tlaxcala, Mexico, has revealed that most of the material had similar values to those found in the closest obsidian source, named El Pared on, Puebla. Nevertheless, initial analyses did not resolve whether these materials came from the same caldera or from a specific obsidian deposit. Here we present a methodology that allows the identification of obsidian subsources. The results reveal that Tlaxcalan populations took advantage of a specific obsidian deposit called Tres Cabezas, Puebla, providing valuable new data to identify associated regional exchange networks.
Research Interests:
Ceramic production from ancient Mesoamerican civilizations is related with cultural and technological evolution processes. Studying ritual objects also provides information on ancient traditions and allows researchers to determine the... more
Ceramic production from ancient Mesoamerican civilizations is related with cultural and technological evolution processes. Studying ritual objects also provides information on ancient traditions and allows researchers to determine the importance of certain materials employed in its manufacture. In this work, a set of 72 of Mayapán’s effigy censers’ sherds was analyzed in situ by using a combination of non-invasive, non-destructive spectroscopic and imaging techniques for material characterization; colorimetry established an initial classification of the pigments present in the objects, XRF provided elemental information, FORS allowed us to describe the molecular characteristics, and hyperspectral imaging established compositional contrasts or similitudes between large regions of the different objects. Pigments were characterized, allowing us to describe the materials used in the decorations of such ritual objects. The pottery matrix was also characterized, leading to a detailed desc...
Research Interests:
In 1952, contemporary artist Federico Silva (Mexico City, 1923-2022) carried out the first outdoor mural painting: The technique at the service of peace. At the end of 2021, the project for the study and conservation of this mural began... more
In 1952, contemporary artist Federico Silva (Mexico City, 1923-2022) carried out the first outdoor mural painting: The technique at the service of peace. At the end of 2021, the project for the study and conservation of this mural began with a diagnosis of its conservation, which was done through a multitechnique study based on the experience acquired in research projects from other contemporary mural paintings. This included the proposal of an adequate conservation strategy to resolve the stability of the painting, since the behavior of the synthetic paints exposed to the different effects of the outdoor environment has altered the perception, form and meaning of the mural. Main results from this approach by documentation and global examination with Visible Imaging and Digital Microscopy, allowed us to describe the color palette and its alterations. Additional examination of cross sections acquired from this mural, allowed a material characterization by means of optical microscopy (OM), micro-hyperspectral imaging, Fourier transformed infrared spectroscopy and X-ray fluorescence spectroscopies.
Research Interests:
Teotihuacan, the main city of the Classic period in Central Mexico (ca. 150/200–650 CE), was among many things, a colorful city. Through its application on mural painting, ceramics, lapidary, bone, textiles, and the human body itself,... more
Teotihuacan, the main city of the Classic period in Central Mexico (ca. 150/200–650 CE), was among many things, a colorful city. Through its application on mural painting, ceramics, lapidary, bone, textiles, and the human body itself, coloring materials gave meaning to the Teotihuacan reality. This research presents color as a socio-technological phenomenon from the archaeology of color, the anthropology of technology, and the application of the concept of technological style.From this scope, pictorial palettes of mural painting fragments from three Teotihuacan architectural compounds were studied by digital microscopy, colorimetry, fiber optic reflectance spectroscopy (FORS), X-ray fluorescence (XRF), Raman spectroscopy, infrared spectroscopy (FTIR), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) in order to identify the color technology of pigments. This approach led us to identify materials shared by the three studied compounds, red and yello...
Research Interests:
In 1952, contemporary artist Federico Silva (Mexico City, 1923-2022) carried out the first outdoor mural painting: The technique at the service of peace. At the end of 2021, the project for the study and conservation of this mural began... more
In 1952, contemporary artist Federico Silva (Mexico City, 1923-2022) carried out the first outdoor mural painting: The technique at the service of peace. At the end of 2021, the project for the study and conservation of this mural began with a diagnosis of its conservation, which was done through a multitechnique study based on the experience acquired in research projects from other contemporary mural paintings. This included the proposal of an adequate conservation strategy to resolve the stability of the painting, since the behavior of the synthetic paints exposed to the different effects of the outdoor environment has altered the perception, form and meaning of the mural. Main results from this approach by documentation and global examination with Visible Imaging and Digital Microscopy, allowed us to describe the color palette and its alterations. Additional examination of cross sections acquired from this mural, allowed a material characterization by means of optical microscopy (OM), micro-hyperspectral imaging, Fourier transformed infrared spectroscopy and X-ray fluorescence spectroscopies.
Research Interests:
Research Interests:
Research Interests:
The sputtering yield amplification (SYA) is a phenomenon based on doping a sputtering target with atoms of higher atomic mass. This doping changes the depth and the direction of the collision cascade in the target surface promoting a... more
The sputtering yield amplification (SYA) is a phenomenon based on doping a sputtering target with atoms of higher atomic mass. This doping changes the depth and the direction of the collision cascade in the target surface promoting a higher ejection of target atoms. In this work, we present a new way of generating the SYA phenomenon without the need of expensive and complex deposition systems. This was accomplished by increasing the working pressure and adding small pieces of W, as dopant element, on the racetrack of a Si target. The physical phenomena necessary to promote the SYA, for our experimental parameters, were analysed in two different deposition chambers and two sizes of sputtering targets. Based on the collisions in the gas phase, a calculation on the number of W atoms returning to the racetrack area was made, considering the number of atoms deposited on the thin films, to determine their effect on the cascade of collisions. In addition, calculations with the simulation of metal transport code were developed to determine the location on the racetrack zone the returning atoms were redeposited.
By using reference samples placed on the racetrack of the Si target, we found that the percentage of SYA depends on the number of dopant atoms redeposited as well as the depth distribution these atoms had in the racetrack surface.
By using reference samples placed on the racetrack of the Si target, we found that the percentage of SYA depends on the number of dopant atoms redeposited as well as the depth distribution these atoms had in the racetrack surface.
Research Interests:
Research Interests:
The sputtering yield amplification (SYA) is a phenomenon based on doping a sputtering target with atoms of higher atomic mass. This doping changes the depth and the direction of the collision cascade in the target surface promoting a... more
The sputtering yield amplification (SYA) is a phenomenon based on doping a sputtering target with atoms of higher atomic mass. This doping changes the depth and the direction of the collision cascade in the target surface promoting a higher ejection of target atoms. In this work, we present a new way of generating the SYA phenomenon without the need of expensive and complex deposition systems. This was accomplished by increasing the working pressure and adding small pieces of W, as dopant element, on the racetrack of a Si target. The physical phenomena necessary to promote the SYA, for our experimental parameters, were analysed in two different deposition chambers and two sizes of sputtering targets. Based on the collisions in the gas phase, a calculation on the number of W atoms returning to the racetrack area was made, considering the number of atoms deposited on the thin films, to determine their effect on the cascade of collisions. In addition, calculations with the simulation o...
Research Interests:
Between 1960 and 1970, the fiber reinforced cement or asbestos-cement was a material used by important muralists such as Messeguer, Benedetto, Flores and. Siqueiros. The challenge of preserving this type of support lies in problems... more
Between 1960 and 1970, the fiber reinforced cement or asbestos-cement was a material used by important muralists such as Messeguer, Benedetto, Flores and. Siqueiros. The challenge of preserving this type of support lies in problems arising from its manufacturing that it presents once it is degraded. Therefore, it was considered pertinent to study materials which in addition to serving as protective and cohesion coatings, were accessible in the commercial field. The objective of this article is to present a study on which the changes in the materials used for conservation of fiber reinforced cement panels were evaluated after being subjected to an accelerated aging cycle, so reproductions were made that simulated the stratigraphy of a modern wall painting with asbestos-cement support. Through organoleptic and instrumental tests, the proposed methodology allowed establishing comparative tables of the properties of the coatings before and during the application, as well as after aging,...
Research Interests:
Adobe masonry is one of the oldest construction systems still in use today, Mexico has an enormous cultural heritage with traditional adobe houses being very representative of the rural communities and their culture. The 2017 Puebla... more
Adobe masonry is one of the oldest construction systems still in use today, Mexico has an enormous cultural heritage with traditional adobe houses being very representative of the rural communities and their culture. The 2017 Puebla Earthquake on September 19th struck the country causing the loss, destruction, and damage of historic buildings in several Mexican states, with the traditional earthen dwellings being the most vulnerable structures to these events. The fast abandonment of the local materials and techniques entails further research regarding the characterization of these construction systems, therefore, reconstruction efforts first require the recovery of the construction technique. After the seismic events, adobe samples of the remaining adobe structures of Jojutla de Juarez were collected. This population was one of the most affected in all the country, and, because of the major losses suffered, the study was conducted to determine the material properties of the dwellin...
Research Interests:
Abstract Capacha is one of the two earliest ceramic complexes known for western Mexico. It dates to a period when sociopolitical complexity was starting to develop in Mesoamerica. An understanding of Capacha pottery technology and... more
Abstract Capacha is one of the two earliest ceramic complexes known for western Mexico. It dates to a period when sociopolitical complexity was starting to develop in Mesoamerica. An understanding of Capacha pottery technology and production are therefore valuable windows into a critical moment of Mesoamerican cultural development. In this paper we analyze the composition of Capacha pottery samples from two sites in the Colima Valley (Colima, Mexico) by means of energy dispersive X-ray fluorescence (n = 100) and thin-section petrography by optical microscopy (n = 42), along with 15 geological clay samples. We look for Capacha pottery compositional diversity, availability and compositional variability in clay deposits in and outside the Colima Valley, and compositional matches between archaeological ceramics and clay deposits. The results indicate that the large majority of pottery analyzed is compositionally homogeneous, in contrast with the wide variation found in macroscopic traits. The results further indicate that Capacha pottery was manufactured in the Colima Valley with largely unprocessed clay(s) obtained locally, with the clay sources closest to the sites sampled providing the best compositional matches. A wide variation in pottery macroscopic characteristics, together with a strong compositional homogeneity of clay deposits over large parts of the Colima Valley, strongly warns against explaining the compositional homogeneity found in the pottery as purely the result of cultural conditioning and standardized cultural practices, with environmental constraints perhaps playing the biggest role in this outcome. This study presents the largest archaeometry-based study of Capacha pottery and the raw materials used in its production.
Research Interests: Archaeology, Geology, Mesoamerican Archaeology, X-Ray Fluorescence (XRF) Spectroscopy, West Mexico (Archaeology), and 10 morePottery, Pottery technology and function, Petrography, Thin Section Petrography, Western Mexico, Arqueología del centro y occidente de México, Pottery Archaeology, Arqueologia Del Occidente De Mexico, Thin Section, and Cultura Capacha
Purísima Concepción, a large-format and unusual panel painting attributed to the 18th century, based on style and the common aspect of the visual tradition of the Virgin Mary found in the Viceroyalty of New Spain, is sheltered at the... more
Purísima Concepción, a large-format and unusual panel painting attributed to the 18th century, based on style and the common aspect of the visual tradition of the Virgin Mary found in the Viceroyalty of New Spain, is sheltered at the Museo Ex-convento San Agustín Acolman-INAH, México, an institution opened in late 1920, and one of the oldest museums in México. In this work, we present the material characterization of the surface layer of the painting by means of a non-invasive methodology, resulting from the combination of imaging and spectroscopic techniques. Analysis of hyperspectral images employing methods such as spectral angle mapper and principal component analysis allowed us to describe spatial distribution of the pigments and manufacturing methods, while XRF and FORS allowed us to record the complex and diverse color palette employed to achieve effects such as brightness, hue, saturation, and even the covering power of this painting.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Jadeite was greatly appreciated by pre-Hispanic cultures in Mesoamerica. Despite its importance, knowledge of its mining sources was lost after the Spanish conquest. In the 1950s the only confirmed jadeite deposits in Mesoamerica were... more
Jadeite was greatly appreciated by pre-Hispanic cultures in Mesoamerica. Despite its importance, knowledge of its mining sources was lost after the Spanish conquest. In the 1950s the only confirmed jadeite deposits in Mesoamerica were found in the Motagua River Fault (MRF), Guatemala. The aim of this study is to present a methodology that is appropriate for the study of archeological jadeite objects using non-destructive spectroscopic and micro-ion beam analysis techniques. This methodology has been applied to perform mineral, elemental, and luminescence characterization of five jadeite samples from the MRF, with white, lilac, and green colors. Fourier-transformed infrared spectroscopy and X-ray diffraction analysis confirmed the presence of jadeite, albite, and omphacite as the main mineral phases in the samples. Elemental maps using particle-induced X-ray emission (PIXE) with a nuclear microprobe and elemental concentration analysis from individual mineral grains using micro-PIXE ...
Research Interests:
Colonial panel paintings constitute an essential part of Latin-American cultural heritage. Their study is vital for understanding the manufacturing process, including its evolution in history, as well as its authorship, dating and other... more
Colonial panel paintings constitute an essential part of Latin-American cultural heritage. Their study is vital for understanding the manufacturing process, including its evolution in history, as well as its authorship, dating and other information significant to art history and conservation purposes. Raman spectroscopy supplies a non-destructive characterization tool, which can be implemented for in situ analysis, via portable equipment. Specific methodologies must be developed, comprising the elaboration of reference panel paintings using techniques and materials similar to those of the analysed period, as well as the determination of the best analysis conditions for different pigments and ground preparations. In order to do so, Raman spectroscopy at 532, 785 and 1064 nm, surface-enhanced Raman spectroscopy (SERS) and a helium-Raman system were applied to a panel painting reference, in combination with X-ray fluorescence analysis. We were able to establish the analysis conditions ...
Research Interests:
We have measured the electron drift velocity, longitudinal diffusion, and the effective ionization coefficients in the gaseous mixture of CF3I-SF6 over the density-normalized electric field intensity E/N, from 375 to 500 Td (1 Td = 10-17... more
We have measured the electron drift velocity, longitudinal diffusion, and the effective ionization coefficients in the gaseous mixture of CF3I-SF6 over the density-normalized electric field intensity E/N, from 375 to 500 Td (1 Td = 10-17 V cm2). A pulsed Townsend technique was used. Overall, the gas mixture compositions were varied from 50 to 90% CF3I. We have found that
Research Interests:
Almost three hundred Spanish colonial missions—or their remains—are scattered over the vast state of Chihuahua in northern Mexico. A few of them still display painted decorations on the wood ceilings and walls. The decorated areas vary... more
Almost three hundred Spanish colonial missions—or their remains—are scattered over the vast state of Chihuahua in northern Mexico. A few of them still display painted decorations on the wood ceilings and walls. The decorated areas vary greatly, from the whole ceiling of the main aisle to just a few square meters in a lateral chapel, and so does the conservation state of the paintings. In this context, the information regarding the paintings’ composition plays a key role in the restoration and conservation processes. For the gathering of such information, we propose a combined methodology for a fast, non-destructive and non-invasive characterization of such paintings with a minimum of techniques. This methodology includes false color infrared imaging as a first approach to determine the composition of large areas of the paintings and the homogeneity of the materials used in the painted areas, followed by small area analysis by X-ray fluorescence and fiber-optics reflectance spectrosc...
Research Interests:
Archaeologists favoring top-down political economy have proposed how political elites controlled the exploitation, production, and distribution of obsidian in different ways. This framework can be traced to a Marxist Asiatic mode of... more
Archaeologists favoring top-down political economy have proposed how political elites controlled the exploitation, production, and distribution of obsidian in different ways. This framework can be traced to a Marxist Asiatic mode of production model, related to the control of a resource by the ruling elite. The reality is that independent-domestic economies represented the basis for the management of obsidian and were responsible for most of the supply in the central Mesoamerican region. Recent investigations have demonstrated the existence of this independent model from the Formative to the Postclassic phases, even in top-down societies such as Teotihuacan, Cantona, and the Mexicas. The following research seeks to provide more evidence surrounding the independent supply system in Central Mexico, specifically for earlier phases. The comparison of archaeological pieces from five Formative sites in Tlaxcala (Amomoloc, La Laguna, Las Mesitas, Tetel, and Xochitécatl-Cacaxtla), and geological samples originally from the El Paredon quarry, resulted in one of the earliest examples where independent economies were responsible for obsidian distribution, discarding the top-down theory.
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ABSTRACT Despite being one of the largest complexes at Teotihuacan, Plaza de las Columnas has been one of the least studied. Recent archaeological discoveries by the Project Plaza de las Columnas Complex revealed that its inhabitants... more
ABSTRACT Despite being one of the largest complexes at Teotihuacan, Plaza de las Columnas has been one of the least studied. Recent archaeological discoveries by the Project Plaza de las Columnas Complex revealed that its inhabitants maintained an evident relationship with the Mayan area. The methodology employed consisted first of a surface examination of the materials via imaging techniques. Afterward, mineralogical characterization was achieved via Infrared (FTIR) and Raman spectroscopies, and X-ray diffraction (XRD) for complementary analysis, while the elemental composition was evaluated by X-ray fluorescence spectroscopy (XRF) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). Results indicate a predominance of objects composed of quartz mixed with carbonates, with a minor number of objects identified as jadeite, albite, omphacite and serpentine. The methodology successfully characterized most of the archaeological objects and establishes new hypotheses regarding the degree of interregional interaction of the inhabitants of Plaza de las Columnas and the degree of access to raw materials and pieces from the Maya area.
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This research deals with the use of Mexican Politec® acrylic artist paint, with its creator, Jose Gutierrez, and with Gunter Gerzso's (a non-figurative painter) application of this acrylic medium in his work. Gutierrez worked at a... more
This research deals with the use of Mexican Politec® acrylic artist paint, with its creator, Jose Gutierrez, and with Gunter Gerzso's (a non-figurative painter) application of this acrylic medium in his work. Gutierrez worked at a synthetic painting manufacturer laboratory in New Jersey during the 1930s. He was part of the Siqueiros New York Experimental Workshop. Back in Mexico, Gutierrez opened a workshop and laboratory at the National Polytechnic Institute (IPN) in 1945, which was dedicated exclusively to expanding the uses of industrial materials applied to art. Here he started to develop specific formulas for Mexican painters, such as Gerzso. In Painting with Acrylics (1965), he explained new ways to obtain different surface qualities with the recently designed acrylic medium, used in solution or as emulsion, and mixed with all kinds of materials. In this work, a technical examination using non-invasive methods of two of Gerzso's paintings, Paisaje de Papantla – Papantl...
Research Interests: Art and Science art
Techinantitla building complex, in the Amanalco neighborhood of the ancient city of Teotihuacan, is famous for the iconography and quality of the mural paintings found in this site. A significant part of this heritage has been lost due to... more
Techinantitla building complex, in the Amanalco neighborhood of the ancient city of Teotihuacan, is famous for the iconography and quality of the mural paintings found in this site. A significant part of this heritage has been lost due to looting. In recent years, an interdisciplinary research project was developed to study the limited patrimony that was left. As part of this study, we first employed geophysical techniques to reconstruct the architectural pattern of the compound’s remaining walls, where other paintings may still be found. Then, we applied a non-invasive methodology to characterize a large set of fragments recovered in the 1980s and to gain information on their pigments and manufacturing techniques. This methodology included False Color Infrared Imaging, X-ray Fluorescence and Fiber-Optics Reflectance Spectroscopy, and led to the identification of hematite, calcite, malachite, azurite and an unidentified blue pigment. The results were compared with a previous study p...
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A burial and a rich offering were found under Room 2 in the Murals Building, Bonampak, a Mayan archaeological site situated in Chiapas, Mexico. This burial may be related with the creation of the famous mural paintings. A rich set of... more
A burial and a rich offering were found under Room 2 in the Murals Building, Bonampak, a Mayan archaeological site situated in Chiapas, Mexico. This burial may be related with the creation of the famous mural paintings. A rich set of jewelry made of green stones was among the different objects found. Green stones have great importance in Mesoamerican cultures, those composed of jadeite being the most appreciated. To characterize the green stones, different spectroscopic techniques were used in a complementary way: Raman and infrared spectroscopies (FT-IR) were used for global mineralogical analysis, while X-ray diffraction (XRD) and X-ray fluorescence (XRF) were applied simultaneously in situ on the artifacts that were not successfully identified by these molecular techniques. In addition, XRF was used to contrasts the elemental information from pieces composed of pyroxenes that may be related to the raw sources of jade in Guatemala. The main minerals identified within the beads and...
Research Interests:
Capacha is one of the two earliest ceramic complexes known for western Mexico. It dates to a period when sociopolitical complexity was starting to develop in Mesoamerica. An understanding of Capacha pottery technology and production are... more
Capacha is one of the two earliest ceramic complexes known for western Mexico. It dates to a period when sociopolitical complexity was starting to develop in Mesoamerica. An understanding of Capacha pottery technology and production are therefore valuable windows into a critical moment of Mesoamerican cultural development. In this paper we analyze the composition of Capacha pottery samples from two sites in the Colima Valley (Colima, Mexico) by means of energy dispersive X-ray fluorescence (n = 100) and thin-section petrography by optical microscopy (n = 42), along with 15 geological clay samples. We look for Capacha pottery compositional diversity, availability and compositional variability in clay deposits in and outside the Colima Valley, and compositional matches between archaeological ceramics and clay deposits. The results indicate that the large majority of pottery analyzed is compositionally homogeneous, in contrast with the wide variation found in macroscopic traits. The results further indicate that Capacha pottery was manufactured in the Colima Valley with largely unprocessed clay(s) obtained locally, with the clay sources closest to the sites sampled providing the best compositional matches. A wide variation in pottery macroscopic characteristics, together with a strong compositional homogeneity of clay deposits over large parts of the Colima Valley, strongly warns against explaining the compositional homogeneity found in the pottery as purely the result of cultural conditioning and standardized cultural practices, with environmental constraints perhaps playing the biggest role in this outcome. This study presents the largest archaeometry-based study of Capacha pottery and the raw materials used in its production.
Research Interests: Pottery (Archaeology), Mesoamerican Archaeology, X-Ray Fluorescence (XRF) Spectroscopy, West Mexico (Archaeology), Pottery technology and function, and 5 moreThin Section Petrography, Western Mexico, Arqueología del centro y occidente de México, Arqueologia Del Occidente De Mexico, and Cultura Capacha
Almost three hundred Spanish colonial missions-or their remains-are scattered over the vast state of Chihuahua in northern Mexico. A few of them still display painted decorations on the wood ceilings and walls. The decorated areas vary... more
Almost three hundred Spanish colonial missions-or their remains-are scattered over the vast state of Chihuahua in northern Mexico. A few of them still display painted decorations on the wood ceilings and walls. The decorated areas vary greatly, from the whole ceiling of the main aisle to just a few square meters in a lateral chapel, and so does the conservation state of the paintings. In this context, the information regarding the paintings' composition plays a key role in the restoration and conservation processes. For the gathering of such information, we propose a combined methodology for a fast, non-destructive and non-invasive characterization of such paintings with a minimum of techniques. This methodology includes false color infrared imaging as a first approach to determine the composition of large areas of the paintings and the homogeneity of the materials used in the painted areas, followed by small area analysis by X-ray fluorescence and fiber-optics reflectance spectroscopy. This methodology was applied to characterize the elemental and molecular composition of the decorations for four missions in Chihuahua in a fast and specific manner, revealing the use of a mix of mineral and organic materials including indigo and cochineal, and detecting differences between the missions. The methodology presented here can be easily applied for the study of a wider number of missions in Chihuahua and other regions to provide outstanding information of materials, pictorial techniques and deterioration conditions.