Maria-Angeles Villegas

• Institute of History, Spanish National Research Council

Se ha realizado un estudio arqueométrico de un conjunto de cerámicas, fechadas entre los siglos II y I a.C., procedentes del oppidum vettón de Ulaca (Solosancho, Ávila). Los objetivos se han centrado en conocer por primera vez las características de las materias primas y la tecnología de producción de las cerámicas de este importante enclave vettón...

MetalEspaña 2020/2021 recoge trabajos sobre todos los tipos de Patrimonio Metálico y aproximaciones de investigación analítica, deontológicos y técnicos. Es una obra conjunta sobre un espacio de encuentro de profesionales, conservadores-restauradores, conservadores, arqueólogos, historiadores del arte, investigadores, alumnos, etc. Las contribucion...

The present contribution discloses the didactic project called COPACUL, which is an innovative didactic experience on Heritage conservation for high school students developed within the background of a more general research project focused on the systematization of methods and protocols for integral conservation of Cultural Heritage materials and t...

A representative set of glass from mostly Indo-Pacific type beads and other materials including a carnelian bead from two Swahili sites of the Ibo Island at Northern Mozambique has been archaeometrically characterized to get insights into its likely provenance within the framework of the Indian Ocean trade networks. Selected samples were examined a...

Optical sol-gel environmental pH sensors have been applied for air evaluation in exhibition halls of the Museo Nacional de Ciencias Naturales (Madrid, Spain). Sensor synthesis and calibration was undertaken following a previous patent by some of the present authors. Monitoring was carried out for one full year to check the influence of meteorologic...

A set of beads made of glass, gastropod mollusk shell, and fishbone from a Swahili occupation level on Ibo Island (northern Mozambique) is dated to the eleventh and twelfth centuries AD. The chemical composition of the glass beads and their chromophores, and the shell and fishbone materials, are studied to understand the local and trading provenanc...

Outdoor and indoor pollutants can affect the conservation of natural history collections. As a first approach to this question, environmental acidity around specimens in the collections of the Natural Science Museum of Barcelona and Botanic Institute of Barcelona (MCNB‐IBB) was measured. Measurements were taken using optical sensors in a number of...

This study explores the relationship between diversity in board composition and the degree of a firm's international activity. Specifically, we posit that board resource variety has a positive relationship with the international activity of the firm and that the strength of board faultlines moderates this relationship. Using data collected from Spa...

With the aim to contrast existing historical documentation with information provided by the own materials, an archeometric study of a representative set of tiles from the Monastery of El Escorial was undertaken. The ensemble, composed of 19 ceramic fragments, covers examples from the 16th and 17th century, either from Talavera or Toledo provenances...

Se exponen los procesos y mecanismos de alteración química de la escultura en vidrio, debidos tanto a su composición química como al efecto de las condiciones ambientales de los medios donde se pueden encontrar o conservar dichas obras escultóricas. Asimismo, se explican los orígenes e interacciones de las alteraciones de origen mecánico, óptico y...

Resumen Dado el interés histórico, artístico y tecnológico de las opalinas de la Real Fábrica de Cristales, se han formulado vidrios opales utilizando como opacificantes CaF2 y P2O5. El objetivo es obtener una composición compatible con el proceso de fabricación de la Fundación Centro Nacional del Vidrio usando el vidrio sonoro regularmente utiliza...

Se estudian las vidrieras de la Catedral de Astorga a partir de dos ejemplos representativos: la Aparición de Jesús resucitado a la Virgen María y el Apóstol San Simón (ss. XVI-XVIII). Se realizó su estudio histórico-artístico y el arqueométrico de una selección de fragmentos de vidrio, con el fin de obtener información sobre su tecnología de produ...

By using silicate inorganic binders and glass waste (colourless or coloured) it is possible to mould technical and artistic elements, which later can be hardened by means of high temperature processing. This procedure is controlled by both the glass transition temperature of binder and of glass waste used as aggregate. "water glass", catalysed with...

Resumen Una reciente intervención arqueológica preventiva en un vertedero de la antigua fábrica de loza de Sargadelos ha permitido recuperar un conjunto importante de materiales cerámicos compuesto por lozas vidriadas y sin vidriar, decoradas y no decoradas, principalmente de la segunda mitad del siglo xix. Los objetivos de la investigación consist...

Museum objects made from metals face the challenge of delaying corrosion in exhibition rooms, showcases and holdings. This study examined some innovative solutions used to protect such items based on sol-gel coatings doped with lanthanum. These coatings were prepared from sols based on TEOS as a precursor. Lanthanum acetate/nitrate was added as a d...

Archaeological excavation of the Institute of Archaeology and Ethnology (Polish Academy of Sciences, PAN) at several Iron Age sites located in West Poland and South Germany has allowed the recovery of an important set of coloured glass beads mostly decorated (6th–4th centuries BC). The present paper summarises the results obtained through the chemi...

This work presents a low cost environmentally friendly alternative to corrosion protection of aluminium alloy based on silica sol-gel thin films doped with lanthanum compounds. Sols were prepared from solutions composed of tetraethylorthosilicate and methyl-triethoxysilane as precursors, distilled water to perform the hydrolysis, absolute ethanol a...

The application of a solid-state electrochemical technique, voltammetry of microparticles (VMP), for studying archeological lead glass is described. Upon attachment to graphite electrodes immersed into aqueous acetate buffer, characteristic voltammetric profiles were obtained for submicrosamples of archeological glasses dated between the 9th and 19...

The state of the art of optical sol-gel sensors applied in the scope of cultural heritage conservation (preventive conservation) is reviewed. Since degradation and corrosion of materials of cultural items take place when neutrality deviations occur, the preparation of thin coatings doped with a pH-sensitive dye arises as a strategy to attain sensor...

En este trabajo se ha realizado la valoración ambiental, tanto en salas como en el interior de vitrinas, en la exposición temporal El último viaje de la fragata Mercedes. La razón frente al expolio, celebrada en el Museo Naval de Madrid. El estudio se realizó mediante un protocolo de seguimiento de la acidez ambiental que utiliza sensores ópticos....

In the present study, a historical set of Late Roman glasses coming from a recently unearthed graveyard located in the small city of Cubas de la Sagra, within the Madrid region (Spain) was compositionally analysed using different techniques such as ultraviolet-visible (UV-Vis) and laser induced fluorescence (LIF) spectroscopies, X-ray fluorescence...

Se ha caracterizado un conjunto de vidrios tardorromanos hallado en las necrópolis de Cubas de la Sagra y depositado actualmente en el Museo Arqueológico Regional de Alcalá de Henares (Madrid). Dicho conjunto procede del yacimiento de Camino de Santa Juana, localizado en el Sur de la Comunidad de Madrid. Los objetivos consistieron en determinar, po...

A thermal colouring process for common soda–lime–silica glasses has been developed by using mirror fragments, to be used as precursors for sculptures. The process involves a heat treatment that enhances the softening and adherence of the base glass pieces to the mirror fragments to form a unique integrated final glass piece (namely the glass sculpt...

This chapter presents the glasses form the point of view of their physical and chemical characteristics and focuses in silicate glasses, the most common compositions concerning archaeological and historical glasses. Besides the fundamentals of the glassy state, which includes the concept of transition temperature and the criteria on the formation o...

This paper presents the results derived from an archaeometric study undertaken on glass samples from the Roman town of Augusta Emerita (Mérida, Spain). The main goal of the research was to provide for the first time some compositional and technological insights into the glass finds unearthed in this town. Glass samples from different sites and chro...

Manuscript Tytpe: Empirical Research Question/Issues: The resource-based view of the firm may provide the theoretical explanation as to how boards can be a source of firm competitive advantage. Directors' experience, knowledge, expertise are valuable, rare, inimitable and non-substitutable resources that make up the board potential. These resources...

The archaeometric characterization of a set of potsherds from six Neolithic sites from the Madrid region has allowed the identification of a new and time-persisting regional technological tradition, based on the deliberated addition of crushed bone as temper in most pottery containers. This is the first known case in Iberia, and is outstanding beca...

Optical properties (absorption and luminescence) of fluorescein molecules encapsulated in porous sol-gel coatings for concentrations ranging from 0.5 to 3.8 wt % are investigated as a function of pH. Absorption spectra of the coatings show main bands at 435 nm and 487 nm for acid and basic pH, respectively. Both peaks appear in the solutions of flu...

Concerning the development of alternatives for replacement of the toxic Chromate surface treatments, the aim of the present study is to design and produce new electrochemically active sol-gel thin films of different composition in the ZrO2-SiO2 system, to act as first chemically active layer for pre-treatments of metallic painted surfaces. For its...

Surface chemical damage on selected historical glasses from 13th to 19th centuries was evaluated by means of atomic force microscopy (AFM). Nano- and microstructure, roughness and topography of ancient glass samples have been compared with those of model glasses prepared by conventional melting at the laboratory with similar compositions to those m...

The application of experimental scientific methods to the study, contextualization, and conservation of ancient glass materials has not yet made much impact on research issues. This paper focuses on the relevance of glass throughout history, showing current available analytical techniques for the systematic study of either the physico-chemical char...

As potential candidates for photonic devices, non-linear materials and coatings, 22 glasses in the TeO2–WO3–PbO system have been formulated and prepared by conventional melting at temperatures ranging between 710 and 750°C. The glass forming area has been determined for a wide region of the corresponding ternary diagram. Structural characterisation...

Rescue archaeological excavations at an urban glass workshop of the 12th century AD in the city of Murcia (Spain) have provided one of the few evidences of glass production in the ancient Islamic territory of Al-Andalus. This paper reports the results derived from a chemical–physical characterisation study carried out on a representative sample set...

Thin coatings optically sensitive against pH are obtained by entrapping erythrosin B molecules in a sol-gel silica matrix. Comparisons between optical spectra of erythrosin B in solutions and those once entrapped in silica coatings are performed for pH ranging from 0.5 to 12.0. Significant differences between both kinds of spectra (solutions and co...

Se ha estudiado un conjunto de 23 perfiles de emplomados (ss. XIII/XIV- XX), procedentes de diferentes lugares europeos. Los perfiles se han estudiado mediante FRX en superficie, previamente eliminada la capa de pasivación y/o la pátina, así como en sección transversal mediante MEBEC. Para contrastar los resultados de FRX, se ha analizado una serie...

This paper reports the results derived from a combined physicochemical characterisation and state of conservation diagnosis study undertaken on a representative ensamble of 15th century Flemish stained glasses and grisailles from the Cartuja de Miraflores Monastery (Burgos, Spain). The main goal of the research was to determine the mechanisms and c...

This paper reports results derived from a chemico-physical characterisation study undertaken on an important ensamble of early 20th century stained glass windows from Madrid and signed by the prestigious and well-known Maumejean Fréres company. The study is part of an on-going project of restoration and conservation carried out by the National Glas...

This paper is focused on the analysis of some metallic materials (lead cames and iron supporting elements) from Spanish Medieval stained glass windows of the Monastery of Pedralbes (Barcelona) and the Cathedral of Seville. The main goal of the research was to assess their current state of conservation by studying processes of decay and corrosion du...

La reciente excavación de la necrópolis celtibérica de Numancia (Garray, Soria) ha permitido recuperar un conjunto de cuentas de vidrio del siglo II a.C. Las cuentas, junto con otros objetos de metaly cerámica, formaban parte de las ofrendas depositadas con el difunto, siendo de tipología anular y coloreadas en azul oscuro, ambar y blanco semitrans...

[ES] La reciente excavación de la necrópolis celtibérica de Numancia (Garray, Soria) ha permitido recuperar un conjunto de cuentas de vidrio del siglo Ha.C. Las cuentas,junto conotros objetos de metaly cerámica, formaban parte de las ofrendas depositadas con el difunto, siendo de tipología anular y coloreadas en azul oscuro,ambar y blanco semitrans...

The influence of cobalt, as a divalent cation, on the crystallization behaviour of the cordierite based glasses was studied. Powdered glass specimens of stoichiometric composition 2MO 2Al2O3 5SiO2 (M=Co and/or Mg) were obtained and thermally treated at several temperatures and times, and the sequence of crystallization and their microstructural evo...

Liquid membrane technologies are gaining a prominent role as a separation technique for the treatment of metal-contained liquid effluents. The present work describes the most important of technologies, the general mechanisms for the metal extraction and some of their applications in the separation of metals. Las tecnologías de membranas líquidas e...

The crystallization behaviour of two glasses with chemical compositions MAl2O4/SiO2=1/2.5, being MNi and equimolar mixtures of Mg and Ni, was investigated. Glasses were prepared by cooling samples melted at 1650 °C. During thermal treatment over the range of temperature up to 1200 °C both glasses were first crystallized to form a β-quartz solid so...

The preparation of ruby glasses in pure silica matrices, as well as the study of the colouration mechanisms have been carried out. For this purpose, TEOS solutions were prepared gold concentrations between 0.0005 and 0.5 wt%. Subsequent to a gelling process at 30 and 60 °C, colour variation was studied as a function of the treatment temperature by...

Introduction The majority of archaeological glasses come from Roman contexts due to the high level of glass production in this historical period. They are beads, vessels, mosaics tiles and, sometimes, glass production wastes (Palomar et al., 2009). The main composition of Roman glasses is soda lime silicate glass, which is characterized by a close...

[ES] El estudio arqueométrico de los patrones de producción cerámica es una herramienta eficaz para determinar el alcance de los cambios socioeconómicos y culturales de las comunidades indígenas de la Zona Arqueológica de Las Médulas (León) como consecuencia del contacto con el mundo romano. En este trabajo se presentan los resultados de la caracte...

[ES] Este trabajo presenta los resultados obtenidos en el estudio arqueométrico de un conjunto de vidrios romanos hallados en las distintas campañas de excavación arqueológica realizadas en el yacimiento de La Dehesa de la Oliva (Patones, Madrid). Los objetivos se centraron en determinar la composición química de los vidrios pertenecientes a las do...