Assessment of a best practise approach for the attribution and authentication of paintings

The ever-growing interest in scientific techniques, able to characterise the materials and rediscover the steps behind the execution of a painting, makes them widely accepted in its investigation. This research discusses issues emerging from attribution and authentication studies and proposes best practise for the characterisation of materials and techniques, favouring the contextualisation of the results in an integrated approach; the work aims to systematically classify paintings in categories that aid the examination of objects. A first grouping of paintings is based on the information initially available on them, identifying four categories. A focus of this study is the examination of case studies, spanning from the 16th to the 20th century, to evaluate and validate different protocols associated to each category, to show problems arising from paintings and explain advantages and limits of the approach. The research methodology incorporates a combined set of scientific techniques (non-invasive, such as technical imaging and XRF, micro-invasive, such as optical microscopy, SEM-EDS, FTIR, Raman microscopy and in one case radiocarbon dating) to answer the questions and, if necessary for the classification, exhaustively characterise the materials of the paintings, as the creation and contribution of shared technical databases related to various artists and their evolution over time is an objective tool that benefits this kind of study. The reliability of a close collaboration among different professionals is an essential aspect of this research to comprehensively study a painting, as the integration of stylistic, documentary and provenance studies corroborates the scientific findings and helps in the successful contextualisation of the results and the reconstruction of the history of the object.

Max Bill in Italia . Lo spazio logico dell'architettura

I Max Bill is an intense giornata of a big fresco. An analysis of the main social, artistic and cultural events throughout the twentieth century is needed in order to trace his career through his masterpieces and architectures. Some of the faces of this hypothetical mural painting are, among others, Le Corbusier, Walter Gropius, Ernesto Nathan Rogers, Kandinskij, Klee, Mondrian, Vatongerloo, Ignazio Silone, while the backcloth is given by artistic avant-gardes, Bauhaus, International Exhibitions, CIAM, war events, reconstruction, Milan Triennali, Venice Biennali, the School of Ulm. Architect, even though more known as painter, sculptor, designer and graphic artist, Max Bill attends the Bauhaus as a student in the years 1927-1929, and from this experience derives the main features of a rational, objective, constructive and non figurative art. His research is devoted to give his art a scientific methodology: each work proceeds from the analysis of a problem to the logical and always verifiable solution of the same problem. By means of composition elements (such as rhythm, seriality, theme and its variation, harmony and dissonance), he faces, with consistent results, themes apparently very distant from each other as the project for the H.f.G. or the design for a font. Mathematics are a constant reference frame as field of certainties, order, objectivity: ‘for Bill mathematics are never confined to a simple function: they represent a climate of spiritual certainties, and also the theme of non attempted in its purest state, objectivity of the sign and of the geometrical place, and at the same time restlessness of the infinity: Limited and Unlimited ’. In almost sixty years of activity, experiencing all artistic fields, Max Bill works, projects, designs, holds conferences and exhibitions in Europe, Asia and Americas, confronting himself with the most influencing personalities of the twentieth century. In such a vast scenery, the need to limit the investigation field combined with the necessity to address and analyse the unpublished and original aspect of Bill’s relations with Italy. The original contribution of the present research regards this particular ‘geographic delimitation’; in particular, beyond the deep cultural exchanges between Bill and a series of Milanese architects, most of all with Rogers, two main projects have been addressed: the realtà nuova at Milan Triennale in 1947, and the Contemporary Art Museum in Florence in 1980. It is important to note that these projects have not been previously investigated, and the former never appears in the sources either. These works, together with the most well-known ones, such as the projects for the VI and IX Triennale, and the Swiss pavilion for the Biennale, add important details to the reference frame of the relations which took place between Zurich and Milan. Most of the occasions for exchanges took part in between the Thirties and the Fifties, years during which Bill underwent a significant period of artistic growth. He meets the Swiss progressive architects and the Paris artists from the Abstraction-Création movement, enters the CIAM, collaborates with Le Corbusier to the third volume of his Complete Works, and in Milan he works and gets confronted with the events related to post-war reconstruction. In these years Bill defines his own working methodology, attaining an artistic maturity in his work. The present research investigates the mentioned time period, despite some necessary exceptions. II The official Max Bill bibliography is naturally wide, including spreading works along with ones more devoted to analytical investigation, mainly written in German and often translated into French and English (Max Bill himself published his works in three languages). Few works have been published in Italian and, excluding the catalogue of the Parma exhibition from 1977, they cannot be considered comprehensive. Many publications are exhibition catalogues, some of which include essays written by Max Bill himself, some others bring Bill’s comments in a educational-pedagogical approach, to accompany the observer towards a full understanding of the composition processes of his art works. Bill also left a great amount of theoretical speculations to encourage a critical reading of his works in the form of books edited or written by him, and essays published in ‘Werk’, magazine of the Swiss Werkbund, and other international reviews, among which Domus and Casabella. These three reviews have been important tools of analysis, since they include tracks of some of Max Bill’s architectural works. The architectural aspect is less investigated than the plastic and pictorial ones in all the main reference manuals on the subject: Benevolo, Tafuri and Dal Co, Frampton, Allenspach consider Max Bill as an artist proceeding in his work from Bauhaus in the Ulm experience . A first filing of his works was published in 2004 in the monographic issue of the Spanish magazine 2G, together with critical essays by Karin Gimmi, Stanislaus von Moos, Arthur Rüegg and Hans Frei, and in ‘Konkrete Architektur?’, again by Hans Frei. Moreover, the monographic essay on the Atelier Haus building by Arthur Rüegg from 1997, and the DPA 17 issue of the Catalonia Polytechnic with contributions of Carlos Martì, Bruno Reichlin and Ton Salvadò, the latter publication concentrating on a few Bill’s themes and architectures. An urge to studying and going in depth in Max Bill’s works was marked in 2008 by the centenary of his birth and by a recent rediscovery of Bill as initiator of the ‘minimalist’ tradition in Swiss architecture. Bill’s heirs are both very active in promoting exhibitions, researching and publishing. Jakob Bill, Max Bill’s son and painter himself, recently published a work on Bill’s experience in Bauhaus, and earlier on he had published an in-depth study on ‘Endless Ribbons’ sculptures. Angela Thomas Schmid, Bill’s wife and art historian, published in end 2008 the first volume of a biography on Max Bill and, together with the film maker Eric Schmid, produced a documentary film which was also presented at the last Locarno Film Festival. Both biography and documentary concentrate on Max Bill’s political involvement, from antifascism and 1968 protest movements to Bill experiences as Zurich Municipality councilman and member of the Swiss Confederation Parliament. In the present research, the bibliography includes also direct sources, such as interviews and original materials in the form of letters correspondence and graphic works together with related essays, kept in the max+binia+jakob bill stiftung archive in Zurich. III The results of the present research are organized into four main chapters, each of them subdivided into four parts. The first chapter concentrates on the research field, reasons, tools and methodologies employed, whereas the second one consists of a short biographical note organized by topics, introducing the subject of the research. The third chapter, which includes unpublished events, traces the historical and cultural frame with particular reference to the relations between Max Bill and the Italian scene, especially Milan and the architects Rogers and Baldessari around the Fifties, searching the themes and the keys for interpretation of Bill’s architectures and investigating the critical debate on the reviews and the plastic survey through sculpture. The fourth and last chapter examines four main architectures chosen on a geographical basis, all devoted to exhibition spaces, investigating Max Bill’s composition process related to the pictorial field. Paintings has surely been easier and faster to investigate and verify than the building field. A doctoral thesis discussed in Lausanne in 1977 investigating Max Bill’s plastic and pictorial works, provided a series of devices which were corrected and adapted for the definition of the interpretation grid for the composition structures of Bill’s main architectures. Four different tools are employed in the investigation of each work: a context analysis related to chapter three results; a specific theoretical essay by Max Bill briefly explaining his main theses, even though not directly linked to the very same work of art considered; the interpretation grid for the composition themes derived from a related pictorial work; the architecture drawing and digital three-dimensional model. The double analysis of the architectural and pictorial fields is functional to underlining the relation among the different elements of the composition process; the two fields, however, cannot be compared and they stay, in Max Bill’s works as in the present research, interdependent though self-sufficient. IV An important aspect of Max Bill production is self-referentiality: talking of Max Bill, also through Max Bill, as a need for coherence instead of a method limitation. Ernesto Nathan Rogers describes Bill as the last humanist, and his horizon is the known world but, as the ‘Concrete Art’ of which he is one of the main representatives, his production justifies itself: Max Bill not only found a method, but he autonomously re-wrote the ‘rules of the game’, derived timeless theoretical principles and verified them through a rich and interdisciplinary artistic production. The most recurrent words in the present research work are synthesis, unity, space and logic. These terms are part of Max Bill’s vocabulary and can be referred to his works. Similarly, graphic settings or analytical schemes in this research text referring to or commenting Bill’s architectural projects were drawn up keeping in mind the concise precision of his architectural design. As for Mies van der Rohe, it has been written that Max Bill took art to ‘zero degree’ reaching in this way a high complexity. His works are a synthesis of art: they conceptually encompass all previous and –considered their developments- most of contemporary pictures. Contents and message are generally explicitly declared in the title or in Bill’s essays on his artistic works and architectural projects: the beneficiary is invited to go through and re-build the process of synthesis generating the shape. In the course of the interview with the Milan artist Getulio Alviani, he tells how he would not write more than a page for an essay on Josef Albers: everything was already evident ‘on the surface’ and any additional sentence would be redundant. Two years after that interview, these pages attempt to decompose and single out the elements and processes connected with some of Max Bill’s works which, for their own origin, already contain all possible explanations and interpretations. The formal reduction in favour of contents maximization is, perhaps, Max Bill’s main lesson.

Trasmission and Reflection (ATR)Far-Infrared Spectroscopy Applied in the Analysis of Cultural Heritage Materials

FIR spectroscopy is an alternative way of collecting spectra of many inorganic pigments and corrosion products found on art objects, which is not normally observed in the MIR region. Most FIR spectra are traditionally collected in transmission mode but as a real novelty it is now also possible to record FIR spectra in ATR (Attenuated Total Reflectance) mode. In FIR transmission we employ polyethylene (PE) for preparation of pellets by embedding the sample in PE. Unfortunately, the preparation requires heating of the PE in order to produces at transparent pellet. This will affect compounds with low melting points, especially those with structurally incorporated water. Another option in FIR transmission is the use of thin films. We test the use of polyethylene thin film (PETF), both commercial and laboratory-made PETF. ATR collection of samples is possible in both the MIR and FIR region on solid, powdery or liquid samples. Changing from the MIR to the FIR region is easy as it simply requires the change of detector and beamsplitter (which can be performed within a few minutes). No preparation of the sample is necessary, which is a huge advantage over the PE transmission method. The most obvious difference, when comparing transmission with ATR, is the distortion of band shape (which appears asymmetrical in the lower wavenumber region) and intensity differences. However, the biggest difference can be the shift of strong absorbing bands moving to lower wavenumbers in ATR mode. The sometimes huge band shift necessitates the collection of standard library spectra in both FIR transmission and ATR modes, provided these two methods of collecting are to be employed for analyses of unknown samples. Standard samples of 150 pigment and corrosion compounds are thus collected in both FIR transmission and ATR mode in order to build up a digital library of spectra for comparison with unknown samples. XRD, XRF and Raman spectroscopy assists us in confirming the purity or impurity of our standard samples. 24 didactic test tables, with known pigment and binder painted on the surface of a limestone tablet, are used for testing the established library and different ways of collecting in ATR and transmission mode. In ATR, micro samples are scratched from the surface and examined in both the MIR and FIR region. Additionally, direct surface contact of the didactic tablets with the ATR crystal are tested together with water enhanced surface contact. In FIR transmission we compare the powder from our test tablet on the laboratory PETF and embedded in PE. We also compare the PE pellets collected using a 4x beam condenser, focusing the IR beam area from 8 mm to 2 mm. A few samples collected from a mural painting in a Nepalese temple, corrosion products collected from archaeological Chinese bronze objects and samples from a mural paintings in an Italian abbey, are examined by ATR or transmission spectroscopy.

Study of the building and decorative materials and techniques used in Hungarian Roman sites

The aims of this research were: - To identify the characteristics, properties and provenance of the building and decorative material found in three Hungarian Roman sites: Nagyharsány, Nemesvámos-Balácapuszta and Aquincum - To provide a database of information on the different sites - To have an overview of main conservation strategies applied in Hungary. Geological studies, macroscopical and microscopical observations, XRD investigations, physical and chemical analyses allowed us to define the characteristics and properties of the different kinds of collected materials. Building stones sampled from Nagyharsány site showed two different kinds of massive limestone belonging to the areas surrounding the villa. Also Building stones sampled from Nemesvámos-Balácapuszta Roman villa proved to be compatible with limestone belonging to local sources. Mural painting fragments show that all samples are units composed of multilayered structures. Mosaic tesserae can be classified as following: -Pale yellow , blackish and pink tesserae are comparable with local limestone; -White tessera, composed of marble, was probably imported from distant regions of the Empire, as the usual practice of Romans. Mortars present different characteristics according to the age, the site and the functions: -Building mortars are generally lime based, white or pale yellow in colour, present a high percentage of aggregates represented by fine sand; -Supporting mortars from both mosaics and mural paintings are reddish or pinkish in colour, due to the presence of high percentage of brick dust and tiles fragments, and present a higher content of MgO. Although the condition of the sites, there is an insignificant content of soluble salts. Database The whole study has allowed us to provide work sheets for each samples, including all characteristics and properties. Furthermore, all sites included in the frame of the research have been described and illustrated on the base of their floor plans, material and construction methodologies. It can be concluded that: 1. In Nagyharsány Archaeological site, it is possible to define a sequence of different construction phases on the base of the study of building material and mortars. The results are comparable with the chronology of the site provided by the archaeologists 2. The material used for construction was of local origin while the more precious ones, used for decorative elements, were probably imported from long distance 3. Construction techniques in Hungary mainly refer to the usual Roman knowledge and practice (Vitruvius); few differences have been found 4. The database will represent an archive for Archaeologists, Historians and Conservators dealing with Roman period in Hungary.

Il caso del Maestro di Ozieri e la cultura pittorica del Cinquecento in Sardegna

La tesi si occupa del rapporto tra il Maestro di Ozieri e la produzione figurativa in Sardegna nella prima metà del Cinquecento. Studia l'uso delle incisioni. Valuta l'influenza della pittura romana e meridionale. Riflette sulla possibile identità straniera del pittore, sulla base delle molte somiglianze con artisti tedeschi e fiamminghi. Si occupa di comprendere quali possano essere considerate le opere autografe e quali quelle eseguite da seguaci e imitatori. Riformula alla luce dei confronti stilistici e delle ricerche in archivio la personalità dell'artista e la sua collocazione cronologica.

Quadri di sintomi. Teoria della immagini, storia dell'arte e scienze umane in medicina

Lo studio analizza il modo in cui la storia dell’arte e la visual culture vengono utilizzate all’interno delle medical humanities, e cerca di suggerire un metodo più utile rispetto a quelli fin qui proposti. Lo scritto è organizzato in due parti. Nella prima parte sono analizzate alcune teorie e pratiche delle scienze umane in medicina. In particolare, ci concentriamo sulla medicina narrativa e sugli approcci con cui la storia dell’arte viene inclusa nella maggioranza dei programmi di medical humanities. Dopodiché, proponiamo di riconsiderare questi metodi e di implementare il ruolo di un pensiero storico e visivo all’interno di tali insegnamenti. Nella seconda parte, alla luce di quanto emerso nella prima, ci dedichiamo a uno studio di caso: la rappresentazione della melanconia amorosa, o mal d’amore, in una serie di dipinti olandesi del Secolo d’Oro. Colleghiamo queste opere a trattati medico-filosofici dell’epoca che permettano di inquadrare il mal d’amore in un contesto storico; in seguito, analizziamo alcune interpretazioni fornite da studiosi e storici dell’arte a noi contemporanei. In particolare, esaminiamo lo studio pionieristico di Henry Meige, pubblicato sulla “Nouvelle iconographie de la Salpêtrière” nel 1899, da cui emerge la possibilità di un confronto critico sia con le posizioni iconodiagnostiche di Charcot e Richer sia con quelle della prima psicoanalisi.

Advanced Spectroscopy for the Study of Colourants in Cultural Heritage

Colourants are substances used to change the colour of something, and are classified in three typology of colorants: a) pigments, b) dyes, and c) lakes and hybrid pigments. Their identification is very important when studying cultural heritage; it gives information about the artistic technique, can help in dating, and offers insights on the condition of the object. Besides, the study of the degradation phenomena constitutes a framework for the preventive conservation strategies, provides evidence of the object's original appearance, and contributes to the authentication of works of art. However, the complexity of these systems makes it impossible to achieve a complete understanding using a single technique, making necessary a multi-analytical approach. This work focuses on the set-up and application of advanced spectroscopic methods for the study of colourants in cultural heritage. The first chapter presents the identification of modern synthetic organic pigments using Metal Underlayer-ATR (MU-ATR), and the characterization of synthetic dyes extracted from wool fibres using a combination of Thin Layer Chromatography (TLC) coupled to MU-ATR using AgI@Au plates. The second chapter presents the study of the effect of metallic Ag in the photo-oxidation process of orpiment, and the influence of the different factors, such as light and relative humidity. We used a combination of vibrational and synchrotron radiation-based X-ray microspectroscopy techniques: µ-ATR-FT-IR, µ-Raman, SR-µ-XRF, µ-XANES at S K-, Ag L3- and As K-edges and SR-µ-XRD. The third chapter presents the study of metal carboxylates in paintings, specifically on the formation of Zn and Pb carboxylates in three different binders: stand linseed oil, whole egg, and beeswax. We used micro-ATR-FT-IR, macro FT-IR in total reflection (rMA-FT-IR), portable Near-Infrared spectroscopy (NIR), macro X-ray Powder Diffraction (MA-XRPD), XRPD, and Gas Chromatography Mass-Spectrometry (GC-MS). For the data processing, we explored the data from rMA-FT-IR and NIR with the Principal Component Analysis (PCA).

I Malvezzi della Ca' Grande: genesi, sviluppo e dispersione di una quadreria bolognese del Settecento

La ricerca ricostruisce e analizza la storia della raccolta d’arte appartenuta al ramo senatorio della famiglia Malvezzi della Ca’ Grande all’interno del variegato panorama collezionistico bolognese settecentesco. La volontà di indagarne lo sviluppo è motivata sia dalla sua esemplarità che dal suo carattere eccezionale. Fondata da Piriteo III (1658-1728) con l’acquisto e la commissione di una cinquantina di dipinti, sia di artisti contemporanei sia di maestri antichi, a cui si aggiungono le opere ereditate dagli antenati, la raccolta fu accresciuta nell’arco di sole tre generazioni. Il principale artefice dell’ampliamento del patrimonio pittorico del casato fu il figlio Sigismondo III (1703-1787), tramite il quale confluì nella quadreria anche l’importante collezione del marchese Paolo Magnani, suo zio materno. Compiendo scelte collezionistiche originali rispetto a quelle d’ordine marcatamente municipalistico, Sigismondo raccolse per la galleria della Ca’ Grande numerose opere di artisti stranieri, glorificati e ricercati in campo europeo, ma estranei di norma al gusto petroniano dell’epoca. Al marchese spetta, inoltre, l’acquisizione del celebre nucleo di opere tre-quattrocentesche, che andò a formare la Camera degli Antichi. Secondo principi illuministici, questi mirava a possedere una sorta di ideale museo privato, ove fosse possibile ammirare il progresso dell’arte petroniana dalle origini sino alla modernità e istituire paragoni fra le più importanti scuole pittoriche. Anche l’erede Piriteo IV (1734-1806) continuò ad ampliare la collezione, compiendo acquisti più limitati, ma non per questo meno significativi. Alla sua morte si estinse la linea maschile del ramo senatorio, per cui la prestigiosa quadreria fu divisa tra le figlie Maria (1780-1865) e Teresa (1782-1811). La raccolta Malvezzi non ebbe la fortuna di confluire entro collezioni durature, cosicché in cinquant’anni quella che fu una delle più importanti gallerie della Bologna settecentesca è stata irrimediabilmente dispersa.

Percorsi urbani e percorsi narrativi: il "racconto dei racconti" di via Zamboni a Bologna

La percezione dello spazio urbano, nella sua complessità, risente inevitabilmente dello stratificarsi, nel tempo, di significati storici, ideologie, archetipi e utopie attraverso i quali la società, nei suoi diversi stadi di sviluppo, ha consolidato l'idea di centro abitato. Nel mondo contemporaneo, la città narrata si sovrappone sempre di più a quella reale, organizzando e sintetizzando i processi interpretativi dei circuiti urbani: al cityscape, il panorama fisico della città, si antepone il suo mindscape, il panorama dell'anima e delle culture urbane. In sintonia con tali prospettive, la presente ricerca si propone di analizzare i processi comunicativi e i paradigmi mediatici che attraversano e ridefiniscono le dinamiche urbane, prendendo in esame gli strumenti e i linguaggi che concorrono a disegnare e raccontare l'immagine di una città. In tale contesto, il progetto prende in considerazione come case study la singolare situazione del distretto universitario intorno a via Zamboni a Bologna: un'arteria di straordinaria bellezza e vitalità, cui tuttavia non corrisponde un'immagine pubblica altrettanto positiva. La tesi ha analizzato in particolare l’immagine pubblica e la percezione di via Zamboni e di piazza Verdi dai primi del Novecento a oggi, in relazione ai principali eventi che le hanno viste come scenari privilegiati. Prendendo in considerazione un arco di tempo di oltre un secolo, sono stati selezionati alcuni momenti topici, occasioni culturali o accadimenti con una forte connotazione simbolica: dalla Liberazione alle manifestazioni del ’77, dalle storiche ‘prime’ del Teatro Comunale agli allestimenti della Pinacoteca, dalle lezioni di professori universitari di chiara fama alle più recenti contestazioni studentesche. Il risultato è un racconto stratificato che attraversa segni e immagini per ricostruire l’iconografia del quartiere attraverso testi, fotografie, filmati, opere d’arte o prodotti multimediali.

Development of new immunochemical and spectroscopic analytical methods for the characterization and conservation of works of art

Cultural heritage is constituted by complex and heterogenous materials, such as paintings but also ancient remains. However, all ancient materials are exposed to external environment and their interaction produces different changes due to chemical, physical and biological phenomena. The organic fraction, especially the proteinaceous one, has a crucial role in all these materials: in archaeology proteins reveal human habits, in artworks they disclose technics and help for a correct restoration. For these reasons the development of methods that allow the preservation of the sample as much as possible and a deeper knowledge of the deterioration processes is fundamental. The research activities presented in this PhD thesis have been focused on the development of new immunochemical and spectroscopic approaches in order to detect and identify organic substances in artistic and archaeological samples. Organic components could be present in different cultural heritage materials as constituent element (e.g., binders in paintings, collagen in bones) and their knowledge is fundamental for a complete understanding of past life, degradation processes and appropriate restauration approaches. The combination of immunological approach with a chemiluminescence detection and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry allowed a sensitive and selective localization of collagen and elements in ancient bones and teeth. Near-infrared spectrometer and hyper spectral imaging have been applied in combination with chemometric data analysis as non-destructive methods for bones prescreening for the localization of collagen. Moreover, an investigation of amino acids in enamel has been proposed, in order to clarify teeth biomolecules survival overtime through the optimization and application of High-Performance Liquid Chromatography on modern and ancient enamel powder. New portable biosensors were developed for ovalbumin identification in paintings, thanks to the combination between biocompatible Gellan gel and electro-immunochemical sensors, to extract and identify painting binders with the contact only between gel and painting and between gel and electrodes.

Essential oils and hydrolates as potential tools for integrated prevention of bacterial diseases in plants

The present work aims to investigate the potential use of natural substances against bacterial plant pathogens. Microdilution tests were therefore carried out in vitro to identify the minimum inhibitory and bactericidal concentrations (MIC and MBC) of several EOs and Hys against selected bacterial pathogens. Commercial products based on a mixture of EOs were in addition assayed with macrodilution experiments against Erwinia amylovora (Ea-causal agent of fire blight). Subsequently, using selected EOs, Hys, and commercial products, ex vivo tests on disease incidence and Ea population dynamics were carried out; the latter experiment was followed by SEM observations. In addition, in vivo resistance induction test was carried out against bacterial leaf of tomato, caused by Xanthomonas vesicatoria (Xv). EOs and Hys showed high bactericidal activity in vitro (MBC <0.1 and <10% for the most active EOs and Hys: Origanum compactum and Thymus vulgaris EOs and Citrus aurantium var. amara Hy, respectively), but they were not effective ex vivo, while resulted very active when used in vivo as resistance inducers in the tomato-Xv pathosystem (relative protection >40%). Differently, commercial products resulted active in all tests, but not as resistance inducers against Xv. An open field trial with commercial products was carried out on strawberry plants naturally infected with Xanthomonas fragariae; the results showed discrete relative protection, concerning that provided by the conventional products based on copper; mostly, the disease severity reduction on those plants treated with EOs commercial products was significant when disease severity resulted high. The papers already published described in the present work investigate (1)the activity of Hys in comparison to EOs with respect to their active volatile content; (2) the potential use of EOs and Hys in cultural heritage; for the restoration of paintings; (3) the induction of resistance caused by plasma-activated water-based root treatments.

Benedetto Gennari ritrattista e pittore di corte in Europa tra Sei e Settecento. I dipinti, la committenza e il diario di lavoro

Cresciuto in una delle botteghe artistiche più prolifiche e illustri della Bologna di metà Seicento, Benedetto Gennari riuscì a distinguersi più degli altri collaboratori del Guercino per una brillante carriera all’estero internazionale che lo portò prima in Francia e poi in Inghilterra, dove seppe ritagliarsi uno spazio di rilievo tra i ranghi della corte, ottenendo finanche la nomina di primo pittore di Giacomo II Stuart. Partendo dall’analisi dei suoi Memoriali, dalla loro natura e dalle ragioni della loro compilazione, il presente studio intende indagare e restituire il profilo dell’artista. Attraverso l’analisi critica della documentazione autografa, di testimonianze edite e inedite e di informazione sui suoi guadagni e sul metodo di lavoro, il lavoro traccia le tappe della lunga attività del pittore, contraddistinta da commissioni di rilievo per importanti mecenati e collezionisti italiani e stranieri. Ben lontano dall’essere un semplice imitatore di provincia, Benedetto divenne un artista di corte, maturando un linguaggio raffinato e a tratti irriverente, che si configura come una personale variante del classicismo bolognese. Su questi aspetti fa luce l’apparato catalografico in cui trovano posto anche opere inedite, riletture iconografiche di quadri noti e indagini tecnico-diagnostiche effettuate, su due dipinti significativi, dal Laboratorio Diagnostico per i Beni Culturali del Dipartimento di Beni Culturali dell’Università di Bologna al fine di documentare la tecnica pittorica dell’artista dopo il suo trasferimento all’estero.

Towards a sustainable approach for Cultural Heritage Conservation: developing micro-structured green materials and analytical protocols for their performance assessment

Cleaning is one of the most important and delicate procedures that are part of the restoration process. When developing new systems, it is fundamental to consider its selectivity towards the layer to-be-removed, non-invasiveness towards the one to-be-preserved, its sustainability and non-toxicity. Besides assessing its efficacy, it is important to understand its mechanism by analytical protocols that strike a balance between cost, practicality, and reliable interpretation of results. In this thesis, the development of cleaning systems based on the coupling of electrospun fabrics (ES) and greener organic solvents is proposed. Electrospinning is a versatile technique that allows the production of micro/nanostructured non-woven mats, which have already been used as absorbents in various scientific fields, but to date, not in the restoration field. The systems produced proved to be effective for the removal of dammar varnish from paintings, where the ES not only act as solvent-binding agents but also as adsorbents towards the partially solubilised varnish due to capillary rise, thus enabling a one-step procedure. They have also been successfully applied for the removal of spray varnish from marble substrates and wall paintings. Due to the materials' complexity, the procedure had to be adapted case-by-case and mechanical action was still necessary. According to the spinning solution, three types of ES mats have been produced: polyamide 6,6, pullulan and pullulan with melanin nanoparticles. The latter, under irradiation, allows for a localised temperature increase accelerating and facilitating the removal of less soluble layers (e.g. reticulated alkyd-based paints). All the systems produced, and the mock-ups used were extensively characterised using multi-analytical protocols. Finally, a monitoring protocol and image treatment based on photoluminescence macro-imaging is proposed. This set-up allowed the study of the removal mechanism of dammar varnish and semi-quantify its residues. These initial results form the basis for optimising the acquisition set-up and data processing.