The homogeneous characterisation of Ariel host stars

The Ariel mission will characterise the chemical and thermal properties of the atmospheres of about a thousand exoplanets transiting their host star(s). The observation of such a large sample of planets will allow to deepen our understanding of planetary and atmospheric formation at the early stages, providing a truly representative picture of the chemical nature of exoplanets, and relating this directly to the type and chemical environment of the host star. Hence, the accurate and precise determination of the host star fundamental properties is essential to Ariel for drawing a comprehensive picture of the underlying essence of these planetary systems. We present here a structured approach for the characterisation of Ariel stars that accounts for the concepts of homogeneity and coherence among a large set of stellar parameters. We present here the studies and benchmark analyses we have been performing to determine robust stellar fundamental parameters, elemental abundances, activity indices, and stellar ages. In particular, we present results for the homogeneous estimation of the activity indices S and log (RHK') , and preliminary results for elemental abundances of Na, Al, Mg, Si, C, N. In addition, we analyse the variation of a planetary spectrum, obtained with Ariel, as a function of the uncertainty on the stellar effective temperature. Finally, we present our observational campaign for precisely and homogeneously characterising all Ariel stars in order to perform a meaningful choice of final targets before the mission launch

Enabling planetary science across light-years. Ariel Definition Study Report

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution

Research and Development for Near Detector Systems Towards Long Term Evolution of Ultra-precise Long-baseline Neutrino Experiments

With the discovery of non-zero value of $\theta_{13}$ mixing angle, the next generation of long-baseline neutrino (LBN) experiments offers the possibility of obtaining statistically significant samples of muon and electron neutrinos and anti-neutrinos with large oscillation effects. In this document we intend to highlight the importance of Near Detector facilities in LBN experiments to both constrain the systematic uncertainties affecting oscillation analyses but also to perform, thanks to their close location, measurements of broad benefit for LBN physics goals. A strong European contribution to these efforts is possible

Les peintures au blanc de zinc des XIXe et XXe siècles : caractérisation physico-chimique multi-dimensionnelle

Cette thèse explore les propriétéset l’emploi des peintures à l’huile à base deblanc de zinc de l’échelle nano- et microscopique jusqu’à l’échelle macroscopique desœuvres d’art.Le blanc de zinc (ZnO), pigment modernedéveloppé à la fin du XVIIIe siècle en tantqu’alternative non toxique au blanc de plomb,a été adopté dans la peinture à l’huile au milieudu XIXe siècle. Initialement utilisé aux côtésdu blanc de plomb, son pouvoir couvrant plusfaible et sa brillance en ont fait un pigment dechoix pour les mélanges de couleurs, les pointslumineux, mais aussi les empâtements et lespréparations. Cependant, il peut provoquer desproblèmes de conservation, par exemple en raison de la formation de savons de zinc, ce qui aété le focus principal de plusieurs études.Connaître ce pigment est donc crucial pourles études techniques des œuvres d’art et leurconservation. Dans ce but, cette rechercheest centrée sur deux axes : l’étude des propriétés physico-chimiques du blanc de zinc et del’ampleur et des modalités d’emploi du pigment.L’analyse de plusieurs types de matériaux estcomplétée avec des recherches documentaires etune enquête auprès des professionnels du patrimoine.Le premier axe est abordé à traversl’analyse, à l’échelle nano- et micromètrique,d’un large corpus, unique et varié, de matériauxd’artiste historiques et modernes des fabricantseuropéens et américains principaux, et d’unesélection d’échantillons issus d’œuvres, qui sontcomparés à des matériaux de référence et desmodèles de peinture. Plusieurs types de techniques d’analyse sont utilisés, allant de méthodes de laboratoire conventionnelles (microscopie optique et électronique, DRX) jusqu’à delarges instrumentations telles que l’accélérateurde particules AGLAE (PIXE, IBIL) et le synchrotron ESRF (DRX à haute résolution angulaire). Plusieurs composés ont été identifiés dansles matériaux de peinture, ce qui met en évidence certaines pratiques et adulterations desfabricants de couleurs. L’hydrozincite, probable produit de dégradation du ZnO, a été identifié dans plusieurs échantillons. Cette étudesouligne, parmi les matériaux historiques etmodernes, des différences de composition, detaille des particules de ZnO et de comportementde luminescence. La morphologie et la taille desparticules de ZnO et la pureté des matériauxanalysés suggèrent une synthèse par méthodeindirecte. La variété des comportements de luminescence, affectés également par d’autres facteurs liés au pigment et à son environnement,est, au contraire, plus difficile à interpréter.Le deuxième axe est abordé à partir descampagnes de fluorescence X sur une cinquantaine d’œuvres analysées in-situ dans lesmusées, et l’étude détaillée d’une sélection depeintures au laboratoire. Cette recherche explore différents emplois du pigment à partird’exemples précoces jusqu’à la moitié du XXesiècle, et constitue une véritable base de données des œuvres qui contiennent du blanc dezinc. En outre, l’étude souligne les limites del’identification du blanc de zinc, notamment surla seule base des analyses non-invasives de fluorescence X. L’intérêt d’un protocole non-invasifpour l’identification du pigment basé sur sa photoluminescence a été mis en valeur, ce qui estcomplémentaire à l’emploi de la cathodoluminescence pour l’étude invasive de matériaux depeinture.Cette recherche constitue donc une référencesur les propriétés physico-chimiques et l’emploidu blanc de zinc, offrant des informations surl’histoire matérielle du pigment et des œuvresd’art modernes en ouvrant des perspectives surleur conservation et authentification.: This thesis explores the propertiesand use of zinc white oil paints, from the nanoand micro-scale up to the macro-scale of artworks.Zinc white (ZnO), a modern pigment developed in the late 18th century as a non-toxicalternative to lead white, was adopted in oilpaint in the middle of the 19th century. Initially used alongside lead white, its lower covering power and brilliance made it a choice forcolour blends and highlights, but also for impastos and grounds. It can cause condition issues,for example due to the formation of zinc soaps,which have been the main focus of several studies.Knowing the pigment is, therefore, crucialfor technical studies and artwork conservation.Thus, this research focuses on two areas: thestudy of the physico-chemical properties of zincwhite and the extent and modalities of use of thepigment. The analysis of several types of material is complemented by documentary researchand a survey among heritage professionals.The first axis is addressed through the analysis, at the nano- and micro-scale, of a large,unique and varied corpus of historical and modern artists’ materials from the leading European and American manufacturers, and a selection of painting samples compared with reference materials and paint mockups. Several analytical techniques are used, from conventionallaboratory methods (optical and electron microscopy, XRD) to large facilities, such as theAGLAE particle accelerator (PIXE, IBIL) andthe ESRF synchrotron (high-angle resolutionXRD). Other compounds than ZnO were identified in the paint materials, shedding light oncertain practices of colour manufacturers andexamples of adulteration. Hydrozincite, a probable degradation product of ZnO, was identifiedin some samples. This study highlights differences in the composition and size of ZnO particles between historical and modern materials,as well as a luminescence behaviour that is moredifficult to interpret because it depends on several factors linked to the pigment and its environment. The morphology and size of the ZnOparticles and the purity of the materials analysed suggest synthesis via indirect method.The second axis is based on X-Ray Fluorescence (XRF) spectroscopy campaigns onaround fifty artworks analysed in-situ in museums, and the detailed study of a selection ofpaintings in the laboratory. This research showsdifferent uses of the pigment through examplesfrom the beginning of the 19th up to the mid20th century, which form a reference databaseof artworks containing zinc white. The studyalso calls into question the identification of zincwhite, particularly when solely based on XRFanalyses. The interest in a non-invasive protocol for pigment identification based on its photoluminescence was highlighted, which is complementary to the use of cathodoluminescencefor the invasive study of paint materials.This research constitutes a reference onthe physico-chemical properties and use of zincwhite; it provides information on the materialhistory of the pigment and modern artworks,opening up new perspectives for artwork conservation and authentication

Lego® bricks and their educative peculiarities in the Italian primary school perspective

The game, since ancient times, has represented a privileged dimension in children's maturation and growth processes. From Piagetian studies to Freudian theories, the idea attested is that by playing children learn to manage and cope with the outside world by making contact with reality. In fact the game can take on different connotations and pass from a free, spontaneous game to a structured game, with a regulatory function and a strongly oriented structure. The different types of elements, that make up the structured material, are with each other in a relationship of equality, order or symmetry in accordance with some variables that characterize their essence: the shape, the colour, the dimensions, the consistency, the manipulability, etc. Jean Piaget emphasized, unequivocally, how knowledge passes from the need to concretely manipulate objects and actions on objects in the world to the ability to mentally represent them in an increasingly abstract and symbolic way. The thesis that here we intend to support is that an appropriate and varied use of structured materials (and, specifically, Lego® bricks due to their particular configuration) favours the acquisition of some mathematical concepts as processes and as objects. Starting from reflections on the use of structured materials in the teaching of Mathematics at school, we focused on the usefulness of Lego® bricks. In particular, we present a project concerning the study of arithmetic multiplication and its properties, to be presented to 6-7 year old primary school students. The activities will be effectively realized thanks to the collaboration with a start-up dedicated to the promotion of scientific culture and the teaching of S.T.E.M. The project as a whole foresees to deal with various topics within the curricular path of primary and lower secondary school. They are faced according to criteria that are not the traditional ones of school times and ways but for "connected concepts": starting from the proposal of a problem we try to dissect mathematical concepts that derive from its resolution, according to paths / guide suggested by the teachers and by the operative files. For example, in the pilot project aimed at a second class, multiplication in the set of natural numbers and its properties are dealt with and, through the guidance of the teacher, we then move on to address the concepts of similarity, fully exploiting the potential characteristic of Lego® bricks; it is possible, in fact, to deal with the latter notion both in the plane and, above all, in the three-dimensional space

An analytical survey of zinc white historical and modern artists’ materials

Abstract This study is the first systematic survey of a large corpus of zinc white (ZnO) artists’ materials. Zinc white is a white pigment developed within the wave of 19th-century technological developments in the paint industry. The composition, particle morphology and size, and luminescence of 49 zinc white samples from artists’ materials were characterized, including three references of known synthesis methods (indirect and direct) and synthesized by the authors (ZnO nanosmoke). The corpus included historical and modern zinc white pigment powders and paint materials from the leading European and American color manufacturers. The study aims to characterize and evaluate the variability of the properties of zinc white and its paint formulations. The reference materials presented properties in agreement with the literature: indirect ZnO exhibited submicron prismoidal blue-luminescent particles of higher purity than direct ZnO, which had larger acicular green-luminescent particles. ZnO nanosmoke presented acicular (tetrapod-like) blue/green-luminescent nanoparticles. Composition, particle morphology, size, and documentary sources suggested a production via the indirect method for the analyzed corpus. However, the luminescence behavior was more complex to interpret. The fundamental emission of ZnO was not always detected, even in pure ZnO powders. Three trends were identified: smaller ZnO particles for the most recent samples; green luminescence connected to larger particle size; fewer trace elements, and of the same type (i.e., lead, sulfur) for historical materials. Another interesting finding was the detection of hydrozincite in some powders, likely a degradation product of ZnO. In terms of methodology, cathodoluminescence proved a valuable tool for pigment identification. The study provides a database of zinc white references for pigment and artwork analysis

Nanomaterials for combined stabilisation and deacidification of cellulosic materials : the case of iron-tannate dyed cotton

The conservation of textiles is a challenge due to the often fast degradation that results from the acidity combined with a complex structure that requires remediation actions to be conducted at several length scales. Nanomaterials have lately been used for various purposes in the conservation of cultural heritage. The advantage with these materials is their high efficiency combined with a great control. Here, we provide an overview of the latest developments in terms of nanomaterials-based alternatives, namely inorganic nanoparticles and nanocellulose, to conventional methods for the strengthening and deacidification of cellulose-based materials. Then, using the case of iron-tannate dyed cotton, we show that conservation can only be addressed if the mechanical strengthening is preceded by a deacidification step. We used CaCO3 nanoparticles to neutralize the acidity, while the stabilisation was addressed by a combination of nanocellulose, and silica nanoparticles, to truly tackle the complexity of the hierarchical nature of cotton textiles. Silica nanoparticles enabled strengthening at the fibre scale by covering the fibre surface, while the nanocellulose acted at bigger length scales. The evaluation of the applied treatments, before and after an accelerated ageing, was assessed by tensile testing, the fibre structure by SEM and the apparent colour changes by colourimetric measurements.Article; Funding details: China Scholarship Council, CSC; Funding details: Horizon 2020 Framework Programme, H2020, 646063; Funding text 1: Funding: This work received funding from the China Scholarship Council (CSC) and from the European Union’s Horizon 2020 Research and Innovation Programme under the NanoRestArt Project (Grant 646063).</p