Francisco Ager
Universidad de Sevilla, Departamento de Física Aplicaca I, Faculty Member
Not many manuscript maps have been the object of material analysis so far. A portolan chart, signed and dated by Juan Vespucci in 1520, was studied in this research, conserved at the Archivo General de Indias in Seville (Spain). It is... more
Not many manuscript maps have been the object of material analysis so far. A portolan chart, signed and dated by Juan Vespucci in 1520, was studied in this research, conserved at the Archivo General de Indias in Seville (Spain). It is made on parchment and depicts the coasts and islands of Europe and Africa. It is the oldest portolan chart made in Seville, being unusual in applying hand stamp for decorative figures. The map was analysed by different non-invasive techniques: infra-red and ultraviolet light, digital microscope and X-ray fluorescence (XRF). The main goals of this study were to identify the materials used, as well as to detect retouching or restoration work. Results showed that the entire parchment was first covered with a white layer made of lead white (Pb), calcite or gypsum (Ca). The principal pigments used were vermilion (Hg), yellow ochre (Fe), azurite (Cu) and a copper-based green pigment (Cu) and carbon black. The letters were probably written with an iron-gall i...
Research Interests:
Analysis of nitrogen in metallic materials using X-ray spectrometry (EDS, PIXE) is subjected to large errors due to two factors: the low nitrogen contents in the steels (usually below 0.3 wt.%) and the presence of interfering L-lines of... more
Analysis of nitrogen in metallic materials using X-ray spectrometry (EDS, PIXE) is subjected to large errors due to two factors: the low nitrogen contents in the steels (usually below 0.3 wt.%) and the presence of interfering L-lines of the main metallic components (Fe, Cr, Ni,…). These factors prevent the use of SEM, TEM, micro-PIXE and other microanalytical techniques for the
Research Interests:
Several fragments of a gilded railing were found in the archaeological excavations carried out in Écija (Spain), among the remains of a collapsed temple. The alloy composition and the gilding procedure used for its manufacture are of... more
Several fragments of a gilded railing were found in the archaeological excavations carried out in Écija (Spain), among the remains of a collapsed temple. The alloy composition and the gilding procedure used for its manufacture are of interest for a complete archaeological knowledge of the artefact. The common use of IBA techniques directly on the objects for their analysis is not possible due to the thick corroded patinas that they exhibit due to the burial environment. However, non-destructive analyses of a few selected fragments have been done using PIXE and XRF techniques in combination with Gamma-Ray Transmission. Indeed, as was previously shown [1,2], bronze objects can be characterized in a completely non-destructive way using the combination of these techniques. This work, shows the applicability of that method to artefacts made of leaded copper alloy, which is the case of samples studied, for which some problems could arise from the lead segregations present in these kind of alloys. We have found that this railing contains low amounts of Sn and Sb, and that the gilding was most probably obtained using a gold leaf.
Research Interests:
The synthesis of thin films of Ag-SiO2, Ag-TiO2 and Ag-TiO2-SiO2 cermet materials is described. The preparation method consists in a sol-gel process based in the dip-coating technique to obtain thin films of a composite material... more
The synthesis of thin films of Ag-SiO2, Ag-TiO2 and Ag-TiO2-SiO2 cermet materials is described. The preparation method consists in a sol-gel process based in the dip-coating technique to obtain thin films of a composite material containing the oxidized metal and the corresponding ceramic material (TiO2 and/or SiO2). The films, prepared on quartz, were finally heated or irradiated to induce the
Research Interests: Engineering, Materials Science, Microstructure, Scanning Electron Microscopy, Transmission Electron Microscopy, and 10 moreSol Gel Process, Thin Film, Absorption spectroscopy, Composite Material, Optical Properties, Ceramic, CHEMICAL SCIENCES, X ray diffraction, Scanning Electron Microscope, and Microstructures
Research Interests: Engineering, Materials Science, Microstructure, Applied Physics, Scanning Electron Microscopy, and 15 moreTransmission Electron Microscopy, Sample Preparation, Focused Ion Beam, Differential scanning calorimetry, Mathematical Sciences, Physical sciences, Nucleation, Nucleation and Growth, Chemical Analysis, Thermal Analysis, Differential Thermal Analysis, Thermogravimetric Analysis, Cross Section, Microstructures, and Electron Beam
Research Interests: Engineering, Materials Science, Photocatalysis, Ultraviolet, Thin Film, and 13 moreUv Radiation, Physical sciences, Band Gap, Nonylphenol, CHEMICAL SCIENCES, Anatase, Waste Water, Photodegradation, Visible Light, Titanium oxide, Stoichiometry, Energy Source, and Rutherford Backscattering Spectrometry
Research Interests:
Research Interests:
Confocal micro X-ray fluorescence (CXRF) is gaining considerable interest due to its ability to provide compositional and spatial information that are typically obtained using standard micro-invasive and/or micro-destructive techniques... more
Confocal micro X-ray fluorescence (CXRF) is gaining considerable interest due to its ability to provide compositional and spatial information that are typically obtained using standard micro-invasive and/or micro-destructive techniques (e.g., SEM-EDX), without the need of sampling. In this work, the specifics of the new CXRF device named μXRF-CONCHA from the Centro Nacional de Aceleradores of the University of Seville will be presented. The development of this equipment is intended to the study in situ of paintings in order to obtain depth profiles of pictorial layers by a no-destructive way. This investigation consists in studying the viability of this device for the study of pictorial layers of old paintings. The challenge consists in determining if the results obtained allow distinguishing the sequence of the paint layer and their composition. Several experimental paint multilayers have been analyzed to evaluate this setup. This paper shows that μXRF-CONCHA will be able to provide important information in order to understand and interpret the choice, palette, and technique of painters from the past.
Research Interests:
ABSTRACT Archeological silver–copper pieces often show surface enrichments in silver, either intentional or fortuitous. When this happens, non-destructive techniques like PIXE (Proton Induced X-ray Emission) and XRF (X-Ray Fluorescence)... more
ABSTRACT Archeological silver–copper pieces often show surface enrichments in silver, either intentional or fortuitous. When this happens, non-destructive techniques like PIXE (Proton Induced X-ray Emission) and XRF (X-Ray Fluorescence) are not sufficient to access the whole bulk pieces because their penetration depths are typically of a few tens microns. If the archeological pieces cannot be cut or polished, it is necessary to apply other non-destructive techniques to access the bulk pieces. That way, archeological bronze pieces have been successfully studied combining XRF (or PIXE) with GRT (Gamma-Ray Transmission).
Research Interests:
Research Interests:
In some zones of Antarctica’s cold and dry desert, the extinction of cryptoendolithic microorganisms leaves behind inorganic traces of microbial life. The extinction of these microorganisms is considered to be the best terrestrial... more
In some zones of Antarctica’s cold and dry desert, the extinction of cryptoendolithic microorganisms leaves behind inorganic traces of microbial life. The extinction of these microorganisms is considered to be the best terrestrial analogue of the disappearance of possible life on early Mars. In the present study, sandstone rock samples from several sites of the Dry Valleys known to harbour
Research Interests:
ABSTRACT For the past years, different therapies based on steroid hormone supplementation or modulators of estrogen receptors have been used after menopause to prevent or manage osteoporosis. Although these treatments seem to be... more
ABSTRACT For the past years, different therapies based on steroid hormone supplementation or modulators of estrogen receptors have been used after menopause to prevent or manage osteoporosis. Although these treatments seem to be beneficial, they have some negative effects in the uterus and breast. The objective of this study was to assess variations for the concentrations of K, Ca, Mn, Fe, Cu, Zn, and Se in uterine tissue of Wistar rats. Ovariectomized rats were subjected to estrogen, progesterone, raloxifene, and tibolone supplementation and compared with nonovariectomized control animals. Elemental contents determined by the particle-induced X-ray emission (PIXE) technique revealed major alterations in Fe, Ca, Mn, and Se in the uterus of ovariectomized rats relative to control animals. After ovariectomy, a significant increase in Ca and Fe and a significant decrease in Mn and Se contents were determined in the uterus. For the ovariectomized groups in which animals received raloxifene, tibolone, estrogen, and estrogen combined with progesterone supplementation, an overall recovery in Mn, Fe, and Se contents was verified. Elemental concentration in the progesterone-supplemented group did not significantly differ from ovariectomized animals receiving placebo. The alterations found for ovariectomized animals receiving placebo and progesterone suggest tissue impairment and trace element imbalance, contrasting with the remaining supplemented groups where an enhancement of tissue activity might justify similar concentration levels relative to controls, because most of the elemental contents altered after ovariectomy.
Research Interests:
Research Interests:
Research Interests:
... E-mail The Corresponding Author , I. Ortega-Feliu a , E-mail The Corresponding Author , M.Á. Ontalba-Salamanca f , E-mail The Corresponding Author and FJ Ager a , d , E-mail The Corresponding Author. a Centro Nacional de Aceleradores,... more
... E-mail The Corresponding Author , I. Ortega-Feliu a , E-mail The Corresponding Author , M.Á. Ontalba-Salamanca f , E-mail The Corresponding Author and FJ Ager a , d , E-mail The Corresponding Author. a Centro Nacional de Aceleradores, Avd. Thomas A. Edison, 7 Isla de ...
Research Interests:
... FJ Ager Corresponding Author Contact Information , E-mail The Corresponding Author , a , b , MD Ynsa b , JR Domínguez-Solís c , MC López ... techniques, in this paper we study leaves of wild type and transgenic A. thaliana plants... more
... FJ Ager Corresponding Author Contact Information , E-mail The Corresponding Author , a , b , MD Ynsa b , JR Domínguez-Solís c , MC López ... techniques, in this paper we study leaves of wild type and transgenic A. thaliana plants grown in a cadmium-rich environment under ...
Research Interests:
... a, Centro Nacional de Aceleradores, Av. Thomas A. Edison s/n, E-41092 Sevilla, Spain. b, Instituto de Bioquı́mica Vegetal y Fotosı́ntesis, Av. ... [2] JR Domı́nguez-Solı́s, G. Gutiérrez-Alcalá, L. Romero and C. Gotor. J. Biol. Chem.,... more
... a, Centro Nacional de Aceleradores, Av. Thomas A. Edison s/n, E-41092 Sevilla, Spain. b, Instituto de Bioquı́mica Vegetal y Fotosı́ntesis, Av. ... [2] JR Domı́nguez-Solı́s, G. Gutiérrez-Alcalá, L. Romero and C. Gotor. J. Biol. Chem., 276 (2001), p. 9297. ...
Research Interests:
ABSTRACT The surface enrichment of archeological silver–copper alloys, either intentional or due to corrosion processes, has been known for many years. The most used non-destructive techniques, such as particle-induced X-ray emission... more
ABSTRACT The surface enrichment of archeological silver–copper alloys, either intentional or due to corrosion processes, has been known for many years. The most used non-destructive techniques, such as particle-induced X-ray emission (PIXE) and X-ray fluorescence (XRF) are surface techniques, with penetration depths typically ranging from a few microns to a few tens of microns. Therefore, these techniques could produce results which are not representative of the bulk composition of the alloy.In order to gain insight into the silver enrichment process and the effects on the data obtained with these techniques, a set of silver roman denarii were cross sectioned and analyzed at the Centro Nacional de Aceleradores micro-PIXE facility. Elemental maps show silver surface enriched layers up to 250 μm thick. Besides, silver-enriched surface layers are not found for alloys with 96–98 wt.% Ag.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Francisco de Zurbarán was one of the greatest painters of the Spanish Golden Age, whose artworks are scattered all over the world. Unfortunately, there are hardly any exhaustive studies on the pigments that he used. In this work, four... more
Francisco de Zurbarán was one of the greatest painters of the Spanish Golden Age, whose artworks are scattered all over the world. Unfortunately, there are hardly any exhaustive studies on the pigments that he used. In this work, four canvas paintings attributed to the Zurbarán Workshop were studied. Each of them presents the figure of a different saint in a peculiar scene isolation: Saint Bruno, Saint Francis of Assisi, Saint Dominic of Guzman, and Saint Peter Martyr. Nevertheless, the painting of Saint Peter Martyr shows a superior quality in both technique and colours, so it is not clear whether this canvas was also made by the Workshop or actually by Zurbarán himself, as some art historians claim.Coinciding with conservation and restoration works, the paintings were analysed initially with non-invasive techniques such as ultraviolet photography (UV), infrared reflectography (IRR) and X-ray fluorescence (XRF) for the characterization of the pigments. Those studies were complement...
Research Interests:
La reflectografía infrarroja (IRR) se ha vuelto un método de registro de imagen clásico para el estudio de obras pictóricas. Esa técnica revela la presencia de dibujos preparatorios. Aunque poco explorado, este registro contiene también... more
La reflectografía infrarroja (IRR) se ha vuelto un método de registro de imagen clásico para el estudio de obras pictóricas. Esa técnica revela la presencia de dibujos preparatorios. Aunque poco explorado, este registro contiene también información que ayuda a la identificación de los pigmentos presentes en la superficie de la obra. Ese trabajo propone analizar estándares de referencia realizados con pigmentos típicos del siglo XVI. Los objetivos son establecer la opacidad y transparencia características de cada material, considerar la influencia de la superposición de capas de distintos materiales y evaluar el comportamiento de distintos equipos. Para el estudio de las pruebas se emplearon cuatros dispositivos registrando una parte especifica del espectro infrarrojo. A la luz de esos primeros resultados, se propone una metodología para la evaluación preliminar de los pigmentos empleados en obras pictóricas antiguas. Con ello, se pretende mejorar la estrategia de análisis mediante otras técnicas puntuales.
Research Interests:
Research Interests:
espanolHoy en dia, el estudio de objetos antiguos de metal incluye el analisis por medio de metodos fisico-quimicos no destructivos desarrollados en las decadas pasadas. Uno de los parametros mas importantes que deben conocerse de una... more
espanolHoy en dia, el estudio de objetos antiguos de metal incluye el analisis por medio de metodos fisico-quimicos no destructivos desarrollados en las decadas pasadas. Uno de los parametros mas importantes que deben conocerse de una muestra es su composicion quimica, ya que esta informacion contribuye significativamente a la determinacion de varias suposiciones y a la respuesta de muchas preguntas que surgen mientras se estudia un objeto de gran valor historico. La fluorescencia de rayos X es una tecnica bien conocida y muy empleada en el analisis elemental de objetos antiguos de metal y el nuevo desarrollo del microhaz focalizado de rayos X descrito en este texto incrementa su adecuacion para el estudio de tecnicas antiguas de fabricacion y decoracion. Esta tecnica de analisis superficial se complementa con la tecnica de transmision de rayos gamma, que ha sido utilizada para la estimacion de la composicion en el interior de monedas de plata-cobre y objetos realizados en otras ale...
Research Interests:
Trabajo presentado a la "Primera Reunion de la Red de Ciencia y Tecnologia para la Conservacion del Patrimonio" (TechnoHeritage) celebrada en Madrid del 28 al 29 de Junio del 2011.
Trabajo presentado al I Congreso Internacional “El Patrimonio Cultural y Natural como motor de desarrollo: Investigacion e Innovacion” celebrado en Jaen del 26 al 28 de enero del 2011.
Research Interests:
Trabajo presentado en el 14th International Symposium on Radiation Physics, celebrado en Cordoba (Argentina) del 7 al 11 de octubre de 2018
Research Interests:
Resumen del trabajo presentado a las VI Jornadas CPAN celebradas en Sevilla (Espana) del 20 al 22 de octubre de 2014.-- et al.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
... Most of them are based in the idea of drawing an Ag-profile from the surface to the bulk of the object (LA-ICP-MS [11], PIXE and RBS [1]). Within this study a set of three complementary XRF methodologies is proposed to be ... Coins... more
... Most of them are based in the idea of drawing an Ag-profile from the surface to the bulk of the object (LA-ICP-MS [11], PIXE and RBS [1]). Within this study a set of three complementary XRF methodologies is proposed to be ... Coins preservation state and pre-analysis treatment. ...
Research Interests:
Research Interests:
Research Interests:
Particle induced X-ray emission (PIXE) and nuclear microprobe (NMP) have been used in an exploratory work to study elemental alterations in tissues of experimental animals submitted to osteoporosis preventive treatments. Osteopathologies... more
Particle induced X-ray emission (PIXE) and nuclear microprobe (NMP) have been used in an exploratory work to study elemental alterations in tissues of experimental animals submitted to osteoporosis preventive treatments. Osteopathologies have been associated with several factors, such as hormonal disturbances, metabolic aberrations, low dietary Ca and vitamin D intake, excess of iron, among other possible factors. Hormonal treatments seem