Articles by Jose Luis Ruvalcaba
Prohibida la reproducción total o parcial por cualquier medio sin la autorizacíón escrita del tit... more Prohibida la reproducción total o parcial por cualquier medio sin la autorizacíón escrita del titular de los derechos patrimoniales.
Papers by Jose Luis Ruvalcaba
Los aztecas utilizaron una cantidad importante de minerales azul-verdosos generalmente designados... more Los aztecas utilizaron una cantidad importante de minerales azul-verdosos generalmente designados como turquesas para hacer ofrendas a sus dioses. Nuestro estudio propone de determinar la composición química de los minerales azules del disco de mosaico de la ofrenda 99 encontrado durante las excavaciones del Templo Mayor de México-Tenochtitlán, antigua capital azteca, y observar el uso de estos en la manufactura de este artefacto. El objetivo es proponer una primera evaluación de las diferentes especies minerales presentes a partir del análisis in situ mediante la técnica no destructiva de fluorescencia de rayos X (XRF), comparando los resultados obtenidos con los de una base de datos de minerales. El presente estudio lleva a precisar la teoría de las “turquesas culturales” propuesta por Weigand et al. (1977) y retomada por Kim et al. (2003). Esta teoría sugiere que la mayoría de las sociedades mesoamericanas, al largo del tiempo, han dado un valor simbólico al color azul-verde y han empleado minerales azul-verdosos para confeccionar particularmente sus objetos de ofrendas. No obstante, podemos pensar que la fabricación de los objetos podía hacerse sin preocupación en la elección de la materia prima mezclando diferentes especies minerales de la familia de las “turquesas culturales”. Este último punto se discute en el caso de las ofrendas del Templo Mayor cuyo estudio revela la ausencia de mezcla intencional de especies minerales en la confección de cada objeto y un uso casi exclusivo de “turquesas químicas” como materia prima. El segundo objetivo de este estudio alberga la procedencia de la turquesa química. Hoy en día, no se conoce ninguna mina de turquesa dentro del antiguo territorio mesoamericano, lo que nos lleva a preguntarnos sobre su procedencia. La teoría actual afirma que esas turquesas procedían de las minas del Suroeste estadunidense localizadas a más de 1800 km de la capital azteca. Nuestro estudio propone comparar las composiciones químicas de turquesas arqueológicas de ofrendas resultantes de las excavaciones del Templo Mayor de México-Tenochtitlan con las de turquesas de procedencia geográfica conocida. Este trabajo se apoya en el postulado de procedencia según el cual la composición química de una turquesa corresponde al lugar de su formación. DOI: 10.13140/RG.2.1.5179.8485
Heritage, 2021
Adobe masonry is one of the oldest construction systems still in use today, Mexico has an enormou... 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...
Heritage Science, 2020
Almost three hundred Spanish colonial missions—or their remains—are scattered over the vast state... 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...
ArchéoSciences, 2014
Les Aztèques utilisèrent une quantité importante de minéraux bleus, généralement désignés comme t... more Les Aztèques utilisèrent une quantité importante de minéraux bleus, généralement désignés comme turquoise pour confectionner, notamment, des of randes. Notre étude propose de déterminer la composition chimique des minéraux bleus du disque de mosaïque de l'of rande 99 issu des fouilles du Templo Mayor de México-Tenochtitlán , ancienne capitale aztèque, et d'observer l'usage de ces minéraux dans la manufacture de cet objet. L'objectif est de proposer une première évaluation des dif érentes espèces minérales présentes à partir d'analyses in situ à l'aide de la l uorescence de rayons X en comparant les résultats obtenus à ceux d'une base de données minérale. La présente étude amène à préciser la théorie des « turquoises culturelles » proposée par Weigand et al. (1977) et reprise par Kim et al. (2003). Cette théorie suggère que la plupart des sociétés mésoaméricaines, au cours du temps, ont conféré une valeur symbolique à la couleur bleu-vert et ont employé des minéraux bleus, voire verts, pour confectionner, notamment, leurs objets d'of randes. Toutefois, on peut aussi penser que la fabrication des objets pouvait s'ef ectuer sans préoccupation dans le choix de la matière première en mélangeant dif érentes espèces minérales de la famille des « turquoises culturelles ». Ce dernier point est discuté dans le cas des of randes du Templo Mayor dont l'étude révèle l'absence de mélange intentionnel d'espèces minérales dans la confection de chaque objet et un usage quasi-exclusif des « turquoises minérales » comme matière première.
ArchéoSciences / Journal of Archaeometry
ABSTRACT
Revista Mexicana de Ciencias Geológicas
Fossil fish specimens from the Múzquiz Lagerstätte (Late Cretaceous) of northern México have been... more Fossil fish specimens from the Múzquiz Lagerstätte (Late Cretaceous) of northern México have been analysed using UV light-induced visible fluorescence microscopy, Particle-induced X-ray Emission (PIXE), X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Specimens examined with UV light microscopy show tightly packed trunk muscle tissues and digestive tract contents, as well as a color gradient from pink to orange to brown associated with the chemical state of the muscle tissues. PIXE analysis shows a 0.346 P/Ca ratio in muscle tissues, as well as a phosphorus increase by a factor of more than four compared to surrounding sediment. Quantitative XRD analysis shows that cryptocrystalline flourapatite (FAP) is the predominant mineral phase and calcite is complementary in the muscle tissues. Nucleation of FAP and calcite may have occurred simultaneously with organic decay, forming adhesive pellets in the soft watery carbonate mud, and caused immobilization of the carcasses....
Journal of Nanotechnology, 2014
Efficient silicon-based light emitters continue to be a challenge. A great effort has been made i... more Efficient silicon-based light emitters continue to be a challenge. A great effort has been made in photonics to modify silicon in order to enhance its light emission properties. In this aspect silicon nanocrystals (Si-NCs) have become the main building block of silicon photonic (modulators, waveguide, source, and detectors). In this work, we present an approach based on implantation of Ag (or Au) ions and a proper thermal annealing in order to improve the photoluminescence (PL) emission of Si-NCs embedded in SiO2. The Si-NCs are obtained by ion implantation at MeV energy and nucleated at high depth into the silica matrix (1-2 μm under surface). Once Si-NCs are formed inside the SiO2we implant metal ions at energies that do not damage the Si-NCs. We have observed by, PL and time-resolved PL, that ion metal implantation and a subsequent thermal annealing in a hydrogen-containing atmosphere could significantly increase the emission properties of Si-NCs. Elastic Recoil Detection measure...
MRS Proceedings, 2014
ABSTRACTIn the Great Temple at Tenochtitlan, the archaeologists found more than 150 offerings wit... more ABSTRACTIn the Great Temple at Tenochtitlan, the archaeologists found more than 150 offerings with thousands of pieces, most of them made on foreign raw materials to the Basin of Mexico. Among these votive contexts, the Chamber III of stage IVa (AD 1440-1469), buried during the government of Moctezuma I, is one of the most richness offerings of the temple. Inside this context, the quantity of greenstone beads is huge, and among them, there is a group of translucent appearance that resembles the green calcite objects from the Huastec region. The purpose of this research is to confirm or discard this probable cultural origin and technological manufacture of these beads. To do that, we perform different analysis with neither non-destructive nor invasive techniques like X-Ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), Raman, Optic Microscopy (OM), and Scanning Electron Microscopy (SEM). By this way we could confirm the similarities among Huastec pieces and these...
X-Ray Spectrometry, 2008
Greenstones were highly appreciated in pre‐Hispanic Mesoamerica. Most of the finest green artifac... more Greenstones were highly appreciated in pre‐Hispanic Mesoamerica. Most of the finest green artifacts were worked in jadeite and other minerals such as serpentine and nephrite. Jadeite, the most precious stone in ancient Mesoamerica, was widely used and traded since the Preclassic Horizon (1500 B.C.). The main beds are located in the Maya region, in the Motagua area of Guatemala. In this work, three pieces of a necklace of greenstones from an offering (corresponding around 155 A.D.) discovered in an extensive excavation carried out in the palatial structure of Xalla, at Teotihuacan site, in the central highlands of Mexico, were studied using external beam particle induced x‐ray emission (PIXE). The necklace is composed by 11 round pieces of green colors ranging from light to dark green. The aim of this study is to determine the elemental composition of the greenstones and to establish the sourcing, trade and relationship between these regions. Thus, several jadeite samples from Manzan...
Zeitschrift für Kristallographie - Crystalline Materials, 2001
A new iron indium germanate has been prepared as polycrystalline powder material which crystalliz... more A new iron indium germanate has been prepared as polycrystalline powder material which crystallizes in the monoclinic system (S.G. C2/m, No. 12). The structure was characterized by X-ray powder diffraction and Rietveld refinement of the resulting diffraction pattern. The cell parameters are a = 6.5124(4) Å, b = 8.5914(5) Å, c = 4.8936(3) Å, β = 102.683(2)°, V = 267.12(3) Å3 and Z = 2. The structure contains R+3 cations (R=Fe, In) almost equally distributed in distorted RO6 octahedral sites. These octahedra are joined by edge sharing forming a hexagonal arrangement on the ab planes. The RO6 octahedra layers are held together by sheets of isolated Ge2O7 diorthogroups constituted by a double tetrahedra sharing a common vertex. This compound has the thortveitite structure and keeps a strong relationship with the FeYGe2O7 germanate, which presents two R+3 sites with six-coordinated (R=Fe) and seven-coordinated (R=Y) oxygens, corresponding to the different symmetry given by the monoclinic...
Microscopy and Microanalysis, 2011
Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tenness... more Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.
ArchéoSciences, 2009
The text is a facsimile of the print edition. Article L.111-1 du Code de la propriété intellectue... more The text is a facsimile of the print edition. Article L.111-1 du Code de la propriété intellectuelle.
Entre los años 2011-‐2012, el Salvamento Carretera Federal 180 Mérida-‐Campeche, registró y exc... more Entre los años 2011-‐2012, el Salvamento Carretera Federal 180 Mérida-‐Campeche, registró y excavó los rasgos arqueológicos denominados estructuras anulares-‐en forma de dona-‐ estos rasgos sin función definida, al ser excavados presentaron restos de piedras calcinadas mezcladas con sedimentos de disGnto color y consistencia, en total fueron exploradas 7 de 13 estructuras registradas. La estraGgraLa de los contextos nos hizo suponer que al interior de las estructuras anulares se llevó a cabo algún evento pirotecnológico para transformar las rocas calizas en posiblemente cal. La geología de la Península de Yucatán, un ambiente kársGco, nos llevó a la búsqueda de una metodología que permiGera disGnguir las calizas quemadas de las calizas naturales. Asimismo, se consideró la caracterización mineralógica además de la disGnción entre los materiales. La propuesta metodológica de disGnción de calcitas geológicas de las antropogénicas, dicha metodología la presentan Chu y colaboradores ...
Elemental concentrations in tree rings have been used to monitor air pollution, volcanic emission... more Elemental concentrations in tree rings have been used to monitor air pollution, volcanic emissions, and the effects of acid precipitations on the tree forest. This possibility has stimulated a wide research to determine which trees species may be suitable for studies of long-term trends in environmental chemistry. Many quantitative methods (wet or dry) have been used to solve this problem, but Particle Induced X-ray Emission (PIXE) seems to be ideal to carry out this kind of analysis. The application of PIXE for the direct analysis of trace element contents on the tree-ring cores has been successful. In this work, several improvements on the analysis of tree-ring cores are presented. External PIXE and RBS were carried out simultaneously in order to measure the concentrations of trace elements and the C and O contents of the wood matrix. A rectangular beam of 1x3 mm was used instead of a circular beam to irradiate a larger area of the tree ring. The study of elemental concentration i...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1999
Zinc is a necessary component in the action and structural stability of many enzymes. Some of the... more Zinc is a necessary component in the action and structural stability of many enzymes. Some of them are well characterized, but in others, Zn stoichiometry and its association is not known. PIXE has been proven to be a suitable technique for analyzing metallic proteins embedded in electrophoresis gels. In this study, PIXE has been used to investigate the Zn content of enzymes that are known to carry Zn atoms. These include the carbonic anhydrase, an enzyme well characterized by other methods and the cytoplasmic pyrophosphatase of Rhodospirillum rubrum that is known to require Zn to be stable but not how many metal ions are involved or how they are bound to the enzyme. Native proteins have been puri®ed by polyacrylamide gel electrophoresis and direct identi®cation and quanti®cation of Zn in the gel bands was performed with an external proton beam of 3.7 MeV energy.
MRS Proceedings, 2014
ABSTRACTSeventy six speckled greenstone items have been recovered on the surrounding structures o... more ABSTRACTSeventy six speckled greenstone items have been recovered on the surrounding structures of the Aztec precinct of the Great Temple of Tenochtitlan. Several researchers have identified the material as marble. Also, these objects have been labeled as Mixtec style due to the raw materials involved in their manufacture as well as their apparent similarity with other known Mixtec objects. The main objective of this essay is to determine the raw materials and the technology employed on its manufacture. Based on earlier composition analysis using Infrared spectroscopy (FTIR) and X-ray Fluorescence (XRF), it became clear that all items are made of the same calcite-serpentine mineral alloy, which probably comes from the Oaxaca region. It is interesting the homogeneity and standardization among these pieces by analyzing them with experimental archaeology and the characterization of their manufacturing traces. Comparing their raw material, morphology and techniques with those of Mixtec ...
MRS Proceedings, 2014
ABSTRACTThe Maya archaeological site of Ek’Balam is located in Yucatán, Mexico. This place is kno... more ABSTRACTThe Maya archaeological site of Ek’Balam is located in Yucatán, Mexico. This place is known for its artistic tradition of reliefs modeled in stucco as well as the rich pictorial and hieroglyphic texts. Although the mural played a key role in the artistic program architectural of elite groups, most of these remains have not been studied, either by its incomplete or fragile condition, or by localization in inaccessible substructures.In this study, technical aspects of the mural paintings from rooms 12 and 50 of the main building of the site are addressed by the spectroscopic analysis of its materials. Optical microscopy was used to observe the layers superposition and pigment distribution, while the stucco and rock support were characterized by X-ray Diffraction (XRD) and X-ray Fluorescence (XRF). Moreover, the chromatic palette composed of different colors and tones of red, yellow, orange, green, blue and black were analyzed mainly with non-invasive techniques using Raman and...
MRS Proceedings, 2014
ABSTRACTIn the study of cultural heritage, most of the analytical techniques are point-specific o... more ABSTRACTIn the study of cultural heritage, most of the analytical techniques are point-specific or give information about small areas of the object. Therefore it is essential to obtain an overview of which points are suitable for these further investigations. To fulfill this, a first imaging study is the best way to proceed. Hereby, we can record the entire piece at once and observe the behavior and relation between different materials of the object. Various types of light can be used to obtain a selection of images and consequently also different information about the artifacts. Among them, infrared (IR) photography can be used as a first analysis, for instance, to reveal the pigments’ response upon interaction with IR radiation.In following we will present results obtained via IR video-photography on a selection of painted objects from the Mexican cultural heritage. These items are analyzed by False Color procedure, where colors are assigned to every grey tone of the pure IR photo...
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Articles by Jose Luis Ruvalcaba
Papers by Jose Luis Ruvalcaba