Examinando por Autor "Arjonilla, Paz"
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Ítem Caracterización de materiales y técnicas de ejecución de los revestimientos decorativos policromados del complejo monumental de la Alhambra y el Generalife(Jaén : Universidad de Jaén, 2019-05-22) Arjonilla, Paz; Domínguez-Vidal, Ana; Ayora-Cañada, María José; Universidad de Jaén. Departamento de Química Física y AnalíticaEn esta tesis se ha llevado a cabo la caracterización de los materiales y las técnicas de ejecución empleados en diferentes revestimientos decorativos policromados del complejo monumental de la Alhambra y Generalife. Los soportes sobre los que se encuentran las policromías estudiadas son mármol, en capiteles tallados, yeserías, madera en alfarjes y ladrillo o tapial en pintura mural. Para la identificación de los pigmentos y productos de degradación se ha empleado una metodología multimodal que incluye el uso de técnicas analíticas no invasivas realizando análisis in situ empleando equipos de fluorescencia de rayos X y microespectroscopía Raman portátiles. Además, se ha profundizado en la investigación mediante el análisis de micromuestras en el laboratorio empleando técnicas no destructivas como la microespectrocopía Raman, la microespectroscopía infrarroja y SEM-EDX. La identificación de aditivos orgánicos se completó con cromatografía de gases acoplada a espectrometría de masas.Ítem Characterization of Wall Paintings of the Harem Court in the Alhambra Monumental Ensemble: Advantages and Limitations of In Situ Analysis(MDPI, 2022-02-23) Arjonilla, Paz; Domínguez-Vidal, Ana; Rubio-Domene, Ramón; Correa, Elena; de-la-Torre-López, María José; Ayora-Cañada, María JoséNon-invasive techniques (X-ray fluorescence, XRF, and Raman spectroscopy) were used for the study of the Hispano Muslim wall paintings. Principal component analysis (PCA) was performed on the semi-quantitative XRF results directly provided by the in-built factory calibrations with minimum user manipulation. The results obtained were satisfactory and highlighted differences and similarities among the measurement points. In this way, it was possible to differentiate the decorations carried out on gypsum plasterwork and the wall paintings over lime plaster. The color palette, revealed by combining the results from XRF and Raman spectroscopies, comprised the pigments hematite, lapis lazuli, cinnabar (in poor conservation state), and possibly, carbon. Evidence of past interventions was also provided by PCA on XRF data, which detected the presence of Pb, Ba, and Zn in some areas. Furthermore, the preparation layers have been studied in detail on crosssections of two microsamples. Several layers of lime plaster with a compact microstructure have been observed. The characteristic of the pictorial layer and the identification of calcium oxalate point to the use of a secco-technique. The main alteration identified was a gypsum surface layer covering the painting and signs of plaster deterioration due to gypsum migration to more internal areas. Finally, the comparison with the observations made by restorers in previous interventions on these paintings revealed the importance of the representativeness gained with the in situ study, which enabled the analysis of a high number of areas.Ítem In situ Raman spectroscopic study of marble capitals in the Alhambra monumental ensemble(Springer, 2016-11-11) Arjonilla, Paz; Domínguez-Vidal, Ana; de-la-Torre-López, María José; Rubio-Domene, Ramón; Ayora-Cañada, María JoséThe marble capitals of five different sites in the Alhambra complex (Granada, Spain), namely the Mexuar, the Hall of the Abencerrages, the Hall of the Kings, the Court of the Myrtles and the Court of the Main Canal, have been investigated. The decoration of the capitals exhibits mainly blue, red, black and gilding motifs with different states of conservation. The work has been carried out in situ by means of a portable Raman micro-spectrometer with an excitation laser of 785 nm. In addition to preserving the artwork with a non-invasive study, the on-site investigation gives a more representative knowledge of the art objects because the measurements are not limited to the samples that can be taken (few and small). The obtained Raman spectra were of good quality despite challenging adverse conditions out of the laboratory. Cinnabar, minium, carbon black, natural lapis lazuli and azurite were the main pigments found. Synthetic ultramarine blue was also detected in a capital as a result of a modern restoration. Degradation products as tin oxide in the gildings and weddellite in the preparation layers were also identified. All the results together with a careful visual inspection can be combined to elucidate the different execution techniques employed to apply the pigments on the marble substrate of the capitals in the Nasrid and Christian periods.Ítem Natural or synthetic? Simultaneous Raman/luminescence hyperspectral microimaging for the fast distinction of ultramarine pigments(Elsevier, 2020) González-Cabrera, María; Arjonilla, Paz; Domínguez-Vidal, Ana; Ayora-Cañada, María JoséGenuine ultramarine has been one of the most precious blue pigments employed since ancient times. It used to be obtained by crushing and grinding the lapis lazuli rock and selectively extracting the blue mineral lazurite. Since 1828, when it was produced the synthetic version, the use of this much less expensive material became widespread and synthetic ultramarine blue replaced the natural one in painting palettes. The distinction between natural and synthetic ultramarine is, therefore, an important goal in authentication issues. Here, we present a hyperspectral microRaman imaging analysis, complemented with the characterization of ultramarine pigment samples in terms of colour, elemental composition and identification of crystalline phases by means of fiber optics reflection spectroscopy (FORS), X-Ray Fluorescence (XRF) and X-Ray diffraction (XRD), respectively. We show that a characteristic luminescence signature, easily detected in the course of standard Raman spectroscopic analysis using 785 nm as excitation, is indicative of the natural origin of the ultramarine blue pigments. Furthermore, simultaneous Raman/luminescence hyperspectral microimages allow the distinction between natural pigments of different quality thanks to the different intensity and spatial distribution of the lazurite characteristic band at 548 cm 1 and those of the luminescent impurities in the region between 1200 and 2000 cm 1. The establishment of a range of quality between different samples of lapis lazuli was also attempted taking into account the variations in the intensity of the Raman bands located at 548 cm 1 and 1286 cm 1. Finally, the feasibility of using the simultaneous Raman/luminescence features for authentication of ultramarine blue in a real historical context, even with non-invasive investigations, is illustrated with examples of different types of blue decorations from several halls of the Alhambra monumental ensemble, in Granada.Ítem Raman and Fourier transform infrared microspectroscopies reveal medieval Hispano–Muslim wood painting techniques and provide new insights into red lead production technology(Wiley, 2019) Arjonilla, Paz; Domínguez-Vidal, Ana; Correa, Elena; Domene-Ruiz, María José; Ayora-Cañada, María JoséThis paper describes the study of two Nasrid polychrome wooden ceilings from the Alhambra monumental ensemble using vibrational spectroscopic techniques. The study is focused on the identification of the constituent materials and execution techniques used employing non‐invasive and non‐destructive scientific investigation methods. Information about both inorganic (pigments) and organic (binders and coatings) materials has been obtained without the need for time‐consuming procedures. A complex stratigraphy involving the use of a protective priming layer of red lead covered with animal glue and white lead was revealed. The identification of Raman signatures of different lead oxide compounds, including lead‐tin oxide (Pb2SnO4), in the priming layer, allowed us to hypothesize the synthesis of red lead (Pb3O4) from litharge (α‐PbO), a common by‐product of the cupellation process used since antiquity for silver production. Furthermore, the pigments employed in hidden drawings found in the reverse of the wood pieces of one of the ceilings were also studied and compared with those found in the visible external face.Ítem Romantic restorations in the Alhambra monument: Spectroscopic characterization of decorative plasterwork in the Royal Baths of Comares(Wiley, 2019) Arjonilla, Paz; Ayora-Cañada, María José; Rubio-Domene, Ramón; Correa, Elena; de-la-Torre-López, María José; Domínguez-Vidal, AnaThe polychrome plasterwork decorations of the Room of the Beds in the RoyalBath of Comares of the Alhambra monumental ensemble have been studiedusing Raman microspectroscopy and complementary techniques. This areakeeps the testimony of the controversial restorations carried out in the 19thcentury in an attempt to imitate the lost original appearance of the authenticNasrid plasterwork. Raman spectroscopy and energy dispersive X‐ray fluores-cence have been employed to identify the pigments and extenders. Scanningelectron microscopy–energy dispersive X‐ray spectroscopy has been used togain additional information about the morphology of the painting layers. Addi-tionally, infrared microspectroscopy provided insight into the nature of theorganic materials employed as binders. Vermillion, synthetic ultramarine blue,hematite, and carbon black were clearly identified in red, blue, brown, andblack decorations by Raman spectroscopy. Green decorations were executedwith a copper‐arsenic pigment that could not be unambiguously identifiedalthough the presence of Raman bands typical of arsenate stretching bandscould point to alteration processes of copper arsenite pigments. Regardingthe execution technique, the pictorial layer was applied over a preparationlayer of white lead that also contained barite using a proteinaceous binder.The presence of anglesite and other phases related to hydrocerussite alterationdue to humidity and salts was also evidenced. Finally, a comparison of thematerials found in this redecoration with those identified in original Nasriddecorations has been performed, revealing noticeable differences in both thematerials and the execution technologiesÍtem Spectroscopic Investigation ofWall Paintings in the Alhambra Monumental Ensemble: Decorations with Red Bricks(MDPI, 2021-04-14) Arjonilla, Paz; Ayora-Cañada, María José; de-la-Torre-López, María José; Correa, Elena; Rubio-Domene, Ramón; Domínguez-Vidal, AnaThe Alhambra Monumental Ensemble (Granada, Spain) is a unique well-preserved palatine city from the medieval Islamic period, and it constitutes the best example of Nasrid architecture. In this work, we focus on the study of one of its most unknown decorations: Wall paintings with the appearance of red bricks. These faux brick decorations are found in many different locations within the Alhambra complex, including both exterior and interior walls, arches and vaults. We have considered locations from different Nasrid reigns to gain information about their characteristics in terms of materials, execution techniques and conservation state. They have been studied combining a non-invasive methodology using portable equipment (X-ray fluorescence (XRF) and Raman spectroscopy) with complementary studies on selected samples (Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) and Raman microimaging). In general, those located in the exterior are poorly preserved, in contrast with the good conservation state of the interior motifs. The red rectangles of these decorations were painted over a white finishing layer, which acted also as the edge lines between these false bricks. The red colour was always due to hematite (α-Fe2O3), as revealed by its characteristic Raman bands. The use of a natural red ochre pigment (very abundant in the region) could be hypothesised considering XRF and SEM-EDS results. In general, the white layer was made of lime mortar and the presence of CaCO3 in the painting layers suggests the use of lime-based techniques (either fresco or mezzo fresco). Only in one of the indoor locations, a different execution technique, based on gypsum (CaSO4 · 2H2O) plaster, was used. The identification of calcium oxalate in this location, in the form of weddellite (CaC2O4 · 2H2O), can be interpreted as the result of organic binder degradation. Furthermore, superficial contamination with gypsum was always detected in outdoor locations.