The young Van Dyck’s fingerprint : a technical approach to assess the authenticity of a disputed painting

The painting Saint Jerome, part of the collection of the Maagdenhuis Museum (Antwerp, Belgium), is attributed to the young Anthony van Dyck (1613–1621) with reservations. The painting displays remarkable compositional and iconographic similarities with two early Van Dyck works (1618–1620) now in Museum Boijmans van Beuningen (Rotterdam) and Nationalmuseum (Stockholm). Despite these similarities, previous art historical research did not result in a clear attribution to this master. In this study, the work’s authenticity as a young Van Dyck painting was assessed from a technical perspective by employing a twofold approach. First, technical information on Van Dyck’s materials and techniques, here identified as his fingerprint, were defined based on a literature review. Second, the materials and techniques of the questioned Saint Jerome painting were characterized by using complementary imaging techniques: infrared reflectography, X-ray radiography and macro X-ray fluorescence scanning. The insights from this non-invasive research were supplemented with analysis of a limited number of cross-sections by means of field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The results demonstrated that the questioned painting’s materials and techniques deviate from Van Dyck’s fingerprint, thus making the authorship of this master very unlikely

Comparison of x-ray absorption and emission techniques for the investigation of paintings

Transmission radiography is an excellent and easy to use method to visualize the internal structure and spatial distribution of heavy Z pigments in the paint layer of 15th to 17th-century panel paintings. It is used to examine the creation process of the artist (e.g. changes in composition, underlying paintings, etc.), to identify older restorations and to solve authentication problems. However, some historical paintings have white lead-based preparatory layers. As a result, the pictorial layer can hardly be visualized in the radiographic images. This problem becomes even more important for 19th and 20th-century paintings due to the introduction of low-Z white pigments. In this investigation, we explored the possibilities of 4 less common radiographic techniques in order to circumvent the mentioned problems. For this, we applied the techniques on 4 panel paintings with an identical figurative composition made by the artist Peter Eyskens

Assessing issues of attribution by means of technical research. A disputed Van Dyck reconsidered

Over the past decades, technical study of artworks proved valuable for addressing issues of attribution.[1] By revealing new information about painting materials and techniques, advanced imaging tools and chemical analyses (e.g. Infrared reflectography, Macroscopic X-ray fluorescence and XRF analysis), we challenge and broaden the current interpretative value of technical investigations of artworks.[2-3] However, despite the recurring introduction of improved diagnostic techniques for the study of paintings and the increasing knowledge of painters’ modus operandi, ‘advances in the methodology of attribution seemed to progress at a snail’s pace.’[4] Hence, the main problem in this research field is how to transform technical data into meaningful information favoring or opposing a specific attribution. This issue can be solved by identifying distinctive materials and techniques as markers in a set of reference artworks for a specific master, workshop, school or period.[5] In this study we assess how an object-based methodology can assist in addressing attribution problems. The method was applied to a case study, i.e. the painting Saint Jerome attributed to Anthony van Dyck [6] of the Antwerp Museum Maagdenhuis, which presented useful evidence on the issue of markers. For the painting Saint Jerome, in-depth art historical and archival research did not result in a clear attribution to Van Dyck. Limited information on the painting’s origin and history could be retraced as the earliest written document on the picture’s provenance dates from 1841. Therefore, Van Dyck’s working procedures were studied by systematically gathering available compositional data derived from a set of 37 reference paintings.[7-16] Additionally, the Antwerp painting’s origin, history, iconographic program, formal features, current condition, physical and technical aspects were examined. Hence, the obtained compositional data of the painting could be studied within a broader art historical and technical context to determine whether the identified painting materials and techniques could be used as markers. This holistic approach thus allowed us to simultaneously assess art historical and technical data to systematically refine our observations and conclusions. As such, the selected markers could be determined for the painting under study, allowing a comparison with the working procedures of Van Dyck. In what follows, we elaborate on the results of the proposed object-based methodology applied to the specific case. Based on the identified working procedures of Van Dyck, the layer build-up, chemical composition and microstructure of the painting were determined by chemical analysis and imaging techniques (e.g. IRR, XRR, Portable XRF, FE-SEM-EDX and MA-XRF scanning). From this working procedure, a set of 4markers could be identified opposing the painting’s current attribution to Van Dyck. First, the identified type of support of the painting Saint Jerome, which is plain-weave canvas with a low density, deviates from Van Dyck’s choice of canvas supports. More specifically, he preferred plain and tabby-weave canvas with a high density. Second, the picture is painted on top of a red chalk-based ground with a grey priming. This canvas preparation type differs from Van Dyck’s usage of white and pale colored chalk-based grounds with various types of primings. Third, the identified blue pigment employed in the painting Saint Jeromefor the depiction of the blue drapery is smalt. Van Dyck, however, favored the usage of the organic pigment indigo to construct blue draperies. Fourth, the identified complex method of paint application to depict the flesh tones in the painting Saint Jerome substantially diverges from Van Dyck’s art practice, who models the human flesh in a single layer. In conclusion, the materials and techniques used in the picture Saint Jeromeclearly deviate from Van Dyck’s working process. These findings thus led us to the conclusion that the painting is not by Anthony van Dyck. References: [1]M. W. Ainsworth.Getty Newsletter2005; 20.1: 4.[2]H.Verougstraete, J. Couvert. La Peinture Ancienne et ses Procédés. Copies, réplique, pastiches, Peeters, Leuven, 2006.[3]K. Van der Stighelen, K. Janssens, G. Van der Snickt, M. Alfeld, B. Van Beneden, B. Demarsin, M. Proesmans, G. Marchal, J.Dik.Art Matters. International Journal for Technical Art History2014; 6: 21.[4]M. W. Ainsworth, in Recent Developments in the Technical Examination of Early Netherlandish Painting. Methodology, Limitations & Perspectives, (Eds: M. Faries, R. Spronk), Brepols, Turnhout, 2003, 137.[5]L. Sheldon, G. Macaro, in European Paintings 15th-18thcentury. Copying, Replicating and Emulating, (Ed: E. Hermens), Archetype Publications, London, 2014, 105-112.[6]L. Philippen, in Commissie van Openbare Onderstand Antwerpen. Bestuurlijk Verslag over het Dienstjaar 1931, Commissie van Openbare Onderstand, Antwerp, 1933, 182-189.[7]L. Alba, M. Jover, M. D. Goya, in The Young Van Dyck, (Eds: A. Vergara, F. Lammertse), Thames & Hudson, London, 2013, 337.[8]M. W. Ainsworth, J. Brealey, E. Haverkamp-Begemann, P. Meyers, Art and Autoradiography: Insights into the Genesis of Paintings by Rembrandt, Van Dyck and Vermeer, The Metropolitan Museum of Art,New York,1987.[9]C. Christensen, M. Palmer, M. Swicklik, in Anthony van Dyck, (Ed: J. Sweeney),National Gallery of Art, Washington, 1990-1991,45.[10]L. Depuydt-Elbaum, R. Ghys. Bulletin de l’Institut Royal du Patrimoine Artistique1999-2000; 28: 251.[11]D. Fend. Jahrbuch des Kunsthistorischen Museums Wien2001; 2: 263.[12]C. Fryklund, F. Lammertse, Masterpiece or Copy? Two Versions of Anthony van Dyck’s St Jerome with an Angel, Museum Boijmans van Beuningen, Rotterdam, 2009.[13]M. Grießer. Jahrbuch des Kunsthistorischen Museums Wien2001; 2: 266.[14]A. Roy. National Gallery Technical Bulletin1999; 20: 50.[15]N. Van Hout,in Looking Through Paintings,(Ed: A. Hermens), Archetype Publications,London1998, 199.[16] R. Woudhuysen-Keller, K. Groen. The Hamilton Kerr Institute Bulletin1988; 1: 119

Influencia de los Componentes Metalúrgicos C, Cr y P en la Permeabilidad del Hidrógeno para Aleaciones Férreas

186 p.La alta dependencia del sistema energético actual con respecto a los combustibles fósiles es un problema al que la humanidad debe hacer frente. Más allá de las consideraciones medioambientales que se puedan asociar a la combustión de los propios combustibles fósiles, las reservas de los mismos son finitas y a largo plazo se verán agotadas. Para afrontar esta situación se plantea el uso de la energía nuclear de fusión como opción tecnológica alternativa a medio plazo. En términos generales se espera que la fusión nuclear pueda suponer una fuente de energía masiva inagotable, limpia y segura.En este contexto el proyecto ITER pretende demostrar la viabilidad tecnológica de la fusión nuclear por confinamiento magnético mediante la construcción de un reactor de fusión que obtenga una potencia superior a la aportada para ponerlo en marcha. Uno de los elementos críticos de este tipo de reactores son las envolturas regeneradoras, a través de las que se debe extraer la energía generada por las reacciones de fusión y, a su vez, proporcionar todo el tritio necesario para mantener la reacción termonuclear durante la vida de la planta.Los materiales que constituirán los diferentes componentes de las futuras plantas de fusión estarán sujetos a la interacción con los isótopos de hidrógeno. El conocimiento de esta interacción resulta fundamental, sobre todo en las mencionadas envolturas regeneradoras, ya que condiciona la viabilidad de regeneración de tritio. Se debe recoger el tritio generado y transportarlo adecuadamente sin que se produzcan pérdidas sustanciales por difusión y absorción en el seno de dichos materiales, de manera que la gestión del combustible tritio se realice de manera eficiente.Todas las envolturas regeneradoras propuestas para ser ensayadas en ITER utilizarán un acero ferrítico-martensítico de baja activación neutrónica como material estructural. Resulta fundamental, por tanto, conocer los parámetros de transporte de los isótopos de hidrógeno en dichos acerosLa presente tesis tiene por objeto analizar los flujos de permeación de hidrógeno en diferentes aleaciones ferríticas con composiciones metalúrgicas controladas para poder analizar el efecto de dicha composición metalúrgica en la permeabilidad del hidrógeno. Para ello se ha empleado la técnica de permeación, una técnica clásica de caracterización del transporte de gas. Las 9 muestras ensayadas son aleaciones adquiridas por EFDA (European Fusion Development Agreement) que cumplen unos estrictos requisitos en cuanto a la composición y a la microestructura. Mediante el ensayo de dichas muestras en la instalación de permeación del Laboratorio de Materiales de Fusión perteneciente al Departamento de Ingeniería Nuclear y Mecánica de Fluidos se ha podido analizar la influencia del C, del Cr y del P en la permeabilidad del hidrógeno para regímenes difusivos. Adicionalmente, se han propuesto expresiones matemáticas para cuantificar la variación de la permeabilidad del hidrógeno en función del contenido de cada uno de los tres componentes mencionados

Relevance and reliability of NO2 and NO monitoring in low-income countries using low-cost sensors

Assessing air quality's impact on human health involves monitoring pollutant concentrations such as NO2, O3, CO, SO2, and particulate matter. While high-income countries rely on expensive reference instruments, low-income nations face technological limitations. This study explores the potential of low-cost scientific devices as a viable solution for these regions. The research focuses on evaluating the reliability of low-cost NO2 sensors and consistency across five identical sensors. Calibration tests in controlled settings reveal a linear model with high coefficients of determination, contrasting with lower coefficients observed during field tests. Variability in intercepts and slopes is evident across time and campaign contexts. Time series analysis using low-cost NO2 sensors showed that many of the tall peaks atop a fluctuating baseline correlates with peaks identified by reference instruments. Additionally, NO gas sensors are also able to identify pollution peaks in monitoring campaigns. Therefore, such affordable sensors provide valuable insights into pollutant concentration trends, offering indicative magnitude information. However, improving calibration and reliability of these sensors necessitates further research

Design and descriptive epidemiology of the Infectious Diseases of East African Livestock (IDEAL) project, a longitudinal calf cohort study in western Kenya

BACKGROUND: There is a widely recognised lack of baseline epidemiological data on the dynamics and impacts of infectious cattle diseases in east Africa. The Infectious Diseases of East African Livestock (IDEAL) project is an epidemiological study of cattle health in western Kenya with the aim of providing baseline epidemiological data, investigating the impact of different infections on key responses such as growth, mortality and morbidity, the additive and/or multiplicative effects of co-infections, and the influence of management and genetic factors. A longitudinal cohort study of newborn calves was conducted in western Kenya between 2007-2009. Calves were randomly selected from all those reported in a 2 stage clustered sampling strategy. Calves were recruited between 3 and 7 days old. A team of veterinarians and animal health assistants carried out 5-weekly, clinical and postmortem visits. Blood and tissue samples were collected in association with all visits and screened using a range of laboratory based diagnostic methods for over 100 different pathogens or infectious exposures. RESULTS: The study followed the 548 calves over the first 51 weeks of life or until death and when they were reported clinically ill. The cohort experienced a high all cause mortality rate of 16% with at least 13% of these due to infectious diseases. Only 307 (6%) of routine visits were classified as clinical episodes, with a further 216 reported by farmers. 54% of calves reached one year without a reported clinical episode. Mortality was mainly to east coast fever, haemonchosis, and heartwater. Over 50 pathogens were detected in this population with exposure to a further 6 viruses and bacteria. CONCLUSION: The IDEAL study has demonstrated that it is possible to mount population based longitudinal animal studies. The results quantify for the first time in an animal population the high diversity of pathogens a population may have to deal with and the levels of co-infections with key pathogens such as Theileria parva. This study highlights the need to develop new systems based approaches to study pathogens in their natural settings to understand the impacts of co-infections on clinical outcomes and to develop new evidence based interventions that are relevant