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The article illustrates the MOLAB research project devoted to the non-invasive investigation of pre-Hispanic and colonial Mesoamerican manuscripts. In the present paper, we provide a description of the project and its aims, listing the artworks so far investigated and describing analytical techniques we employed. A presentation of the data obtained by the scientific analyses is then followed by a description of the main cultural and historical interpretive venues that can be pursued through a strongly interdisciplinary approach such as the one adopted by the MOLAB.

A multidisciplinary approach, including compositional, spectroscopic and microscopic methodologies, is often used for the analysis and identification of pigments in Fine Arts. Although a large part of widely used natural and synthetic pigments contain Fe-oxides and hydroxides, their magnetic characterization is still poorly explored. The application of rock magnetism analyses through fast, cheap and non-destructive measurements, can be instead useful for the identification and discrimination of pigments through their distinctive magnetic properties.In this preliminary study, the magnetic properties of several iron-based commercial pigments together with paintings models and supports, were analyzed.In order to investigate the compositional differences of pigments by means of their magnetic behavior, the magnetic susceptibility, the hysteresis properties and the magnetic susceptibility variation at low and high temperature were measured on selected samples.All the pigments showed different magnetic properties, mainly related to variable proportions of magnetite, hematite and maghemite as the main magnetic carriers.Further studies will be addressed to define a protocol for applying the magnetic techniques to the characterization of pigments, including tests on samples produced by different brands and different periods, with the final aim of integrating the magnetic measurements with the different spectroscopic techniques commonly employed for the preservation and the analysis of cultural heritage.

Magnetic biomonitoring methodologies were applied at Villa Farnesina, Rome, a masterpiece of the Italian Renaissance, with loggias frescoed by renowned artists such as Raffaello Sanzio. Plant leaves were sampled in September and December 2020 and lichen transplants were exposed from October 2020 to early January 2021 at increasing distances from the main trafficked road, Lungotevere Farnesina, introducing an outdoor vs. indoor mixed sampling design aimed at assessing the impact of vehicular particulate matter (PM) on the Villa Loggias. The magnetic properties of leaves and lichens - inferred from magnetic susceptibility values, hysteresis loops and first order reversal curves - showed that the bioaccumulation of magnetite-like particles, associated with trace metals such as Cu, Ba and Sb, decreased exponentially with the distance from the road, and was mainly linked to metallic emission from vehicle brake abrasion. For the frescoed Halls, ca. 30 m from the road, the exposure to traffic-related emissions was very limited or negligible. Tree and shrub leaves of the Lungotevere and of the Villa's Gardens intercepted much traffic-derived PM, thus being able to protect the indoor cultural heritage and providing an essential conservation service. It is concluded that the joint use of magnetic and chemical analyses can profitably be used for evaluating the impact of particulate pollution on cultural heritage within complex metropolitan contexts as a preventive conservation measure.

The article, based on the results of non-invasive scientifical analyses, illustrates the changes occurred in the technology of codex painting in early colonial Mesocamerica.

Presentación de los resultados obtenidos a través de análisis científicos no-destructivos realizadas sobre el Códice Vaticano B, un manuscrito Mesoamericano preservado en la Biblioteca Apostolica Vaticana

In this work the formulation of 20 Johann Faber felt-tip pens commercialized in the 1960s and belonging to and used by the architect and designer Lina Bo Bardi have been investigated by an integrated analytical methodology. Minimally destructive vibrational spectroscopic methods permitted a qualitative interpretation of constituents which could be corroborated and ulteriorly supplemented by more destructive chromatographic techniques. This combined approach constitutes an effective collaboration for an in-depth study chronicling the chemical characterization of the first era of commercially viable felt-tip pen inks by providing for the identification of dyes and separation of their mixtures (triarylmethanes, xanthenes, indigoids, azo dyes, azines), binders (plant gums) and additives (diethylene glycol, phenols/antioxidant, diisoctyl phthalate/plasticizer). The comparison between the early and more recent commercial felt-tip pens has allowed to differentiate dyes, pigments and binders, which may provide a useful reference for future studies on the chemical characterization of historical samples.

The study aims to analyse the vibrations induced by traffic on the Villa Farnesina in Rome. The ancient building was designed and erected by the architect Baldassarre Peruzzi and the walls, vaults and lodges were decorated with frescoes attributable to Raphael and other relevant Italian Renaissance painters. Villa Farnesina is located near the Lungotevere road, therefore it suffers the dangerous effects due to the urban traffic even with heavy vehicles passing, so much so that in the early seventies an anti-vibration paving was built. A six-month geophysical monitoring made it possible to analyse the propagation of the waves on the building, characterizing the vibration due to the current traffic level. The results show the vibration levels recorded on the different floors of the building.

An acquisition campaign of macro-X-ray fluorescence scanning measurements on the vault of the Loggia of Cupid and Psyche, frescoed by Raphael and his workshop in the Villa Farnesina (Rome), supplied the occasion of testing the potentialities for such diagnostic tool/technique in studying wall paintings in situ. In this paper, the methodological approach is considered in depth, to highlight significant problematics deriving from nature of materials, painting technique and spatial peculiarities of this kind of artwork, as well as from the treatment and decoding of raw data. Data obtained through a single-spot XRF campaign, carried out during the past restorations of the Loggia, have been considered for comparisons. Graphical abstract: [Figure not available: see fulltext.]. © 2018, Accademia Nazionale dei Lincei.

Egyptian blue, the oldest man-made blue ever, invented by the Egyptians around 5000 years ago has newly raised to prominence for its very recent finding on Raphael’s Roman fresco the Triumph of Galatea hosted in Villa Farnesina, Rome. This is the first case in the Renaissance after centuries of oblivion. In recent years, due to its peculiar spectroscopic properties, Egyptian blue made itself known for manifold application in numerous and very different fields, far beyond its original purpose. Contrary to its brilliant present, its past remains still obscure, characterized from twists and turns which sporadically let it re-emerge. To track its modifications over centuries and places and piece together its fascinating path which has led it from pyramids to nanoscale applications, a network called BLUENET has been established. It is composed by more than 60 institutions and more than 100 researchers working on this subject and exploiting different aspects of Egyptian blue, from synthesis and its modifications to energetic, medical and forensic applications. A mini-review is given here accounting for the structural properties of such material, its currently applications in medical, forensic, energetics, and the raising questions reawakened by the authors’ finding on the Raphael’s fresco of Villa Farnesina together with their approach to address such issues by establishing a dedicated network composed by researchers from all over the world.

This chapter aims to present the chemical characterization of coloured materials used for painting the five manuscripts held at the Bodleian Library, detailing the spectral markers used for their identification and discussing the potentials and limitations of the molab non- invasive approach.

As part of an ongoing interdisciplinary project, aimed at disclosing pre-Hispanic Mesoamerican codex painting technologies, a set of non-invasive analyses has been carried out by the MOLAB European mobile facility on the two pre-Hispanic codices today held by the Biblioteca Apostolica Vaticana, commonly known among Mesoamericanists as Codex Borgia (Borg. mess. 1) and Codex Vaticanus B (Vat. lat. 3773).

In this paper the data proceeding from non-invasiove chemical analyses performed on five Mesoamerican manuscripts held at the Bodleian Libraries (Oxford) are put in the wider context of current knowledge concerning Mesoamerican codex painting technology, in order to provide a preliminary cultural- historical interpretation aimed at identifying technological similarities among different manuscripts.

Within the frame of a collaboration among the Accademia Nazionale dei Lincei, XGLab-Bruker and ENEA, some of the Renaissance wall paintings decorating Villa Farnesina interiors have been investigated by macro-X-ray fluorescence (MAXRF). In this paper is presented and discussed a case study concerning some sketches discovered about 50years ago during the detachment of painted curtains. Results have brought to light a palimpsest whose discussion calls into question the attribution proposed when it has been discovered.

The philosophical and artistic orientation of Enrico Baj (Italy, 1924–2003) regarding nuclear energy cannot be exclusively reduced to his activism in the Nuclear Art Movement. Baj's interest in science, techniques and technology did not map onto the chronology of this avant-garde movement (1951–1958), but rather was related to the developments in anthropology, philosophy and literature. This studio has as its focus the non-invasive in situ analysis of five of Enrico Baj's paintings which are part of the Archivio Baj collection in Vergiate (Italy): Quamisado II (1951), Bambino magico (1952), Personaggio (1955), Due bambini nella notte nucleare (1956), Spettacolo (1956). Painting materials were investigated thanks to two distinct work sessions of the mobile laboratories of MOLAB-CNR/UNIPG and INFN-CHNet, from October to November 2018. The instruments and know-how of these laboratories were granted to the “Baj Nucleare” project through the access activity to Research Infrastructures offered by E-RIHS.it. This study provided data, which, when cross-checked with previous studies and combined with documents from artistic literature as well as from available secondary sources, have allowed authors to try to better understand Enrico Baj's work process, being able to count on the support of unpublished scientific evidence.

Unexpected finding of Egyptian blue emerged in Raphael’s fresco Triumph of Galatea at Villa Farnesina, in Rome. This pigment is the oldest man-made blue, dating back to Egyptians who manufactured it first and whose occurrence was thought to be lost with Romans. Thanks to advanced imaging techniques it has been possible to non-invasively map its distribution throughout the frescoed surface and to obtain a non-invasive imaging stratigraphic analysis indicating whether pure painting layers, mixtures or overlapping occurred. Egyptian blue identification on Raphael’s Galatea is so far the earliest of sixteenth century, and could be the first step towards its tracking in Renaissance, demonstrating that non-invasive techniques are a mandatory step not only for materials identification but also for understanding art history and its dynamics.

The performance of non-invasive chemical analyses on various pre-Hispanic Mesoamerican codices to chemically characterize their painting materials has recently opened new avenues into research on the ancient Mesoamerican book painting tradition. In this chapter, a comparative effort is undertaken in order to shed light on the technological relationships linking codices pertaining to different scribal traditions. Scientific results are also contrasted with historical data contained in Colonial textual sources, providing information on the paints used by ancient Mesoamerican painters and scribes.

MOLAB is a unique collection of integrated mobile instrumentation established in Italy in 2001 and open from 2004 to transnational access within the European projects Eu-ARTECH (FP6) and CHARISMA (FP7). Its application demonstrated in the last decade that satisfactory analytical results can be obtained through in situ studies of a variety of heritage objects without sampling or moving them to a laboratory, achieving significant overviews on nature and behavior of the inorganic and organic materials of the examined object. The MOLAB in situ non-invasive approach produced a significant change in diagnostic practices, an increase of scientific inputs in heritage studies and conservation, and a positive modification in the relationships between curators, conservators, and scientists, permitting a common language to be established and partnership strengthened. The recent introduction of innovative mobile 2D and 3D imaging systems, setup within the CHARISMA joint research project, significantly extended the MOLAB tools available in the current project IPERION CH (Horizon 2020), widening number and interest of potential users from Europe and associated countries. MOLAB est un ensemble unique d’instruments mobiles intégrés créé en Italie en 2001 et disponible à un accès transnational depuis 2004 dans le cadre des programmes européens Eu-ARTECH (6e PC) et CHARISMA (7e PC). Son utilisation a démontré au cours des dix dernières années que l’on peut obtenir des résultats analytiques de qualité par des travaux in situ sur différents types d’objets du patrimoine sans avoir à prélever des échantillons ou à les transporter dans un laboratoire, et recueillir des informations importantes sur la nature et le comportement des matériaux organiques et inorganiques de l’objet examiné. Les méthodes in situ et non invasives du MOLAB ont favorisé une inflexion notable des pratiques diagnostiques, une augmentation de la production scientifique dans les sciences du patrimoine et la conservation-restauration, ainsi qu’une évolution positive des relations entre conservateurs de musées, restaurateurs et chercheurs, contribuant à l’adoption d’un langage commun et au renforcement des collaborations. L’introduction récente de systèmes mobiles d’imagerie en 2D et en 3D, mis au point grâce aux activités conjointes de recherche de CHARISMA, a considérablement élargi la gamme des outils du MOLAB disponibles dans le cadre du projet en cours IPERION CH (horizon 2020), accroissant ici le nombre et les motivations des utilisateurs potentiels en Europe et dans les pays associés.

Using the MOLAB® non-invasive analytical mobile laboratory, we studied a finely illuminated sixteenth-century Persian manuscript at the Fitzwilliam Museum, Cambridge, UK, in collaboration with its Department of Manuscripts and Printed Books. Three miniatures belonging to the manuscript, but ascribable to different periods, were analyzed in order to identify similarities and differences in the painting materials and techniques used by Safavid artists over a period of 150 years. The use of multiple analytical techniques indicated a common palette characterizing the three decorative schemes, along with some differences mainly regarding the pigment mixture used to obtain brown hues in the first scheme, as well as the presence of different mixtures in green and dark purple areas in the third scheme.

In order to evaluate the effectiveness of cyclododecane (CDD) as a temporary protective coating and consolidating agent for fragile stone materials, this paper focuses on its physicochemical behaviour in terms of its penetration into porous matrices and subsequent sublimation. In particular, a near-infrared spectroscopy (NIR) and NMR in-depth profilometry study has been carried out by monitoring the evaporation/sublimation process of CDD solutions as a function of time. By means of this non-invasive multitechnique approach, the behavior of CDD both on the surface and inside the first millimeters of the stones has been adequately described. It has also been highlighted how the progression of CDD's disappearance within different stones is affected by both substrate porosity and boiling point of the carrier solvent. These results demonstrate the potential of such a method of protocol for non-invasive in situ monitoring of the unconstrained sublimation process of this temporary protective agent. © 2014 Elsevier Masson SAS. All rights reserved.

El uso de la cochinilla en la Mesoamérica prehispánica y colonial está. atestiguado por un gran número de evidencias, tanto materiales como documentarias, pero su estudio en la pintura de códices, o manuscritos pictóricos, ha sido hasta fechas recientes muy somero. En el presente texto presentamos los resultados de análisis científicos no-invasivos recientemente realizados en el marco de un proyecto destinado a la identificación de los materiales colorantes empleados en la manufactura de códices prehispánicos y coloniales.

In this work Raman spectroscopic techniques have been utilized to characterize the vibrational spectral features of orchil dyed wool samples. Specifically, it is noted by surface enhanced Raman spectroscopy that wool dyed purple with two historically used orchil species (Roccella tinctoria and Lasallia pustulata) show spectral differences possibly owing to their specific dye-precursor constituents. The additional natural dyestuff woad (Isatis tinctoria L.) overdyeing the R. tinctoria orchil dyed wool is a further challenge when distinguishing the mixed dye components given by the co-adsorption of the dyestuffs as permitted by the selection rules of surface enhanced Raman spectroscopy. Furthermore, the effects of dilution of the L. pustulata species in its spectral detection have been assessed along with the evaluation of subsequent lichen extract boiling before dyeing which resulted in the detection of a degraded form of the orchil dye. Proof of concept included the surface enhanced Raman spectroscopy (SERS) investigation of a purple dyed tapestry (XVI century) which permitted an aged orchil dye to be determined. This contribution utilizes SERS as a fast, reproducible and specific method for both orchil dye detection and alteration induced by degradation. Copyright © 2014 John Wiley & Sons, Ltd.

In order to realize a surface enhanced Raman spectroscopy (SERS) gel protocol with portable Raman instrumentation, this contribution oversees the optimization of a removable SERS active methylcellulose gel and the applicability of an innovative gelatin substrate. Analytical evaluations by non-invasive portable nuclear magnetic resonance (NMR) profilometry with regards to methylcellulose and gelatin film penetration and removal from an unvarnished painted surface and commercial dyed paper substrates have been carried out, respectively, following successful SERS measurements. Both gels have been specifically prepared in accordance to the substrate under exam so as to simultaneously permit sufficient surface interaction for Raman enhancements to be recorded with limited penetration into or subsequent damage on removal of the matrix under study. This work continues to bridge the gap towards non-invasive SERS measurements and in-situ SERS measurements. Copyright © 2014 John Wiley & Sons, Ltd.

A complete non-invasive characterization by XRF, XRD, near-FTIR and UV–Vis reflectance spectroscopy has been performed on some commercially available violet pigments as well as on pure violet Co-salts also known to be used as pigments. The obtained results show that, after a preliminary elemental characterization, the studied pigments can be easily identified by near-FTIR and UV–Vis spectroscopies since they exhibit peculiar spectral bands in these regions. Among the analyzed samples emerged that the pigment 45350 - “Manganviolett” from Kremer consists of two α- and β-NH4MnP2O7 polymorphs, being α-NH4MnP2O7 the most abundant one; furthermore we found that the pigment R1215D -“Cobalt violet” by Winsor & Newton (no longer available since 2006) displays spectral features that match exactly those of 45820-“Kobaltviolett hell” from Kremer and both are composed by cobalt ammonium phosphate hydrate. Such non-invasive study allowed for the identification of “Manganese Violet” (α-NH4MnP2O7) and anhydrous cobalt phosphate (Co3(PO4)2) on some Boccioni's paintings during MOLAB in situ measurements at the Museo del Novecento (Milano).

In 1946 TAM (Taller de Arte Mural) a group of famous Argentine artists namely Castagnino, Spilimbergo, Urruchua and Colmeiro, realized the decoration of four lunettes placed above the entrances of the Galerias Pacifico in Buenos Aires. Twenty-four samples coming from these lunettes have been analyzed by means the infrared transmission micro-spectroscopy to determine the composition of the preparation layer (mainly composed by gypsum) and the nature of binder (a drying oil), while the investigation of Raman micro-spectroscopy has allowed to identify the inorganic pigments and the synthetic organic dyes present. (C) 2013 The Authors. Published by Elsevier B.V. Selection and peer-review under responsibility of the IA-CS (Italian Association of Conservation Scientists) and University of Antwerp

The new nitrogen-rich oxide N 3 O has been detected in the gas phase by mass spectrometric experiments. The radical has been assigned a minimum lifetime of 0.7 μs and an open-chain NNNO structure in the quartet state. Structures and energies of the N 3 O + precursor ion and the N 3 O radical have been investigated by ab initio calculations.

Low-dimensional carbon nanostructures, such as nanotubes and graphenes, represent one of the most promising classes of materials, in view of their potential use in nanotechnology. However, their exploitation in applications is often hindered by difficulties in their synthesis and purification. Despite the huge efforts by the research community, the production of nanostructured carbon materials with controlled properties is still beyond reach. Nonetheless, this step is nowadays mandatory for significant progresses in the realization of advanced applications and devices based on low-dimensional carbon nanostructures. Although promising alternative routes for the fabrication of nanostructured carbon materials have recently been proposed, a comprehensive understanding of the key factors governing the bottom-up assembly of simple precursors to form complex systems with tailored properties is still at its early stages. In this paper, following a survey of recent experimental efforts in the bottom-up synthesis of carbon nanostructures, we attempt to clarify generalized criteria for the design of suitable precursors that can be used as building blocks in the production of complex systems based on sp(2) carbon atoms and discuss potential synthetic strategies. In particular, the approaches presented in this feature article are based on the application of concepts borrowed from traditional organic chemistry, such as valence-bond theory and Clar sextet theory, and on their extension to the case of complex carbon nanomaterials. We also present and discuss a validation of these approaches through first-principle calculations on prototypical systems. Detailed studies on the processes involved in the bottom-up fabrication of low-dimensional carbon nanostructures are expected to pave the way for the design and optimization of precursors and efficient synthetic routes, thus allowing the development of novel materials with controlled morphology and properties that can be used in technological applications.

This contribution focuses on an analytical evaluation of the use of cyclododecane (CDD) (C12H24) as a temporary protective coating for non-porous stone materials of cultural heritage interest.

With the aim of characterizing ground preparations of paintings by infrared reflection spectroscopy, the CaSO4–H2O system (gypsum/bassanite/anhydrite) has been re-investigated, evaluating and assigning the SO42- and OH overtone and combination bands, respectively, in the ranges 1900–2700 cm−1 and 5000–6000 cm−1 resulting from reflection and high concentration transmission spectra. The second-order modes have been proven to be highly specific, reliable, and less affected by overlap with bands of organic binders and can hence be exploited for the identification of the sulfate hydration phase using infrared (IR) reflection spectroscopy. Subsequently, the characterization and identification of hydration phases in unknown sulfate-based ground preparations on authentic artworks have been carried out noninvasively by fiber-optic reflection IR spectroscopy and on cross-sections by infrared reflection micro-spectroscopy. The spectroscopic data collected both on standards and artworks have been cross-validated by X-ray diffraction.

We show that all-electron relativistic four-component Dirac-Kohn-Sham (DKS) computations, using G-spinor basis sets and state-of-the-art density fitting algorithms, can be efficiently parallelized and applied to large molecular systems, including large clusters of heavy atoms. The performance of the parallel implementation of the DKS module of the program BERTHA is illustrated and analyzed by some test calculations on several gold clusters up to Au(32), showing that calculations with more than 25 000 basis functions (i.e., DKS matrices on the order of 10 GB) are now feasible. As a first application of this novel implementation, we investigate the interaction of the atom Hg with the Au(20) cluster.

The absorption and emission properties of the two components of the yellow color extracted from weld (Reseda luteola L.), apigenin and luteolin, have been extensively investigated by means of DFT and TDDFT calculations. Our calculations reproduce the absorption spectra of both flavonoids in good agreement with the experimental data and allow us to assign the transitions giving rise to the main spectral features. For apigenin, we have also computed the electronic spectrum of the monodeprotonated species, providing a rationale for the red-shift of the experimental spectrum with increasing pH. The fluorescence emission of both apigenin and luteolin has then been investigated. Excited-state TDDFT geometry optimizations have highlighted an excited-state intramolecular proton transfer (ESIPT) from the 5-hydroxyl to the 4-carbonyl oxygen of the substituted benzopyrone moiety. By computing the potential energy curves at the ground and excited states as a function of an approximate proton transfer coordinate for apigenin, we have been able to trace an ESIPT pathway and thus explain the double emission observed experimentally.

Finite-length models of chiral semiconducting carbon nanotubes based on Clar sextet theory allowed carrying out accurate calculations, performed by application of gradient-corrected density functional theory, on the energetic of sidewall reactions. In particular, we analyzed the addition of atomic fluorine and carbene (CH2) to (6,4) and (6,5) nanotubes, finding excellent convergence of reaction energies with respect to the model length and good agreement with literature data. Our study demonstrates the importance of using models of carbon nanotubes based on chemical considerations to evaluate consistently the electronic and reactive properties of the sidewall.

The structural properties of luteolin, apigenin and of all their possible mono-deprotonated species are studied with ab initio methods in vacuo and in solution. Molecular structures have been optimized by MP2 and DFT using different functionals and basis sets. Harmonic vibrational frequency calculations have been performed on the optimized structures to ensure geometries obtained were real minima. All calculations resulted in non-planar structures except for deprotonation in 4' position at the DFT level. An interesting behavior for the torsional potential between phenyl B ring and the 1,4-benzopyrone skeleton has been detected. Therefore, potential energy profiles along this coordinate have been characterized and analyzed in terms of conjugative and steric interactions through the evaluation of the coefficients fitted with an eight-term Fourier expansion. The frontier molecular orbitals and the HOMO-LUMO gap at the different geometries along this torsion curve have been computed and their changes have been thoroughly analyzed. Finally, structural and electronic changes on deprotonation and frontier molecular orbitals for all mono-deprotonated species have been studied. (C) 2008 Elsevier B.V. All rights reserved.