Дисертації з теми "Heritage materials"

Thesis (MEng (Civil Engineering))--Cape Peninsula University of Technology, 2020
The history of the South African construction industry dates as far back as the seventeenth century, with structures such as the Castle of Good Hope, cathedrals, museums and memorials, among many others. Heritage structures represent the history of a country and its development. These structures do not only elaborate on the history, but also embody unique designs and materials used for their construction. This makes historic structures physically distinct from modern constructions. However, heritage structures often show critical signs of deterioration, which threaten their existence thereof. In attempts to rescue these national treasures, the use of Portland cement has been a common practice, but there are problems with using such modern materials. The application of incompatible materials is said to accelerate the deterioration and endanger the authenticity of these monuments. This practice is a result of a misunderstanding of the original material behaviour and has been responsible for the failure of many restoration projects. For developing countries, South Africa in particular, this approach has undoubtedly impacted negatively on the economy, as repeated repairs are necessary. Characterisation of the original cementing materials is the key to compatible restoration of heritage buildings. The research describes the development of an integrated protocol to establish the properties of the original heritage cementing materials. The key objective for the study was to investigate and standardise an analytical procedure whose primary purpose is the identification of major and minor components of heritage cementing materials and binder-to-aggregate ratio, which would be useful for production of repair materials. The results obtained from the experimental investigation into the physical, chemical and mineralogical properties of the original materials from the Castle of Good Hope and Robben Island are presented in this study. The experimental results were analysed for their ability to provide useful data at minimal costs. After that, a standard protocol was developed, incorporating the procedure for sampling as well as preparation of the sample, material analysis and documentation. The standard protocol includes the cohesion test, visual investigation and titration test for analysis of the salts and metal oxides present in the materials. These tests provide relevant data for the search of replica repair materials. The standard protocol will be useful for local heritage authorities, as it could be incorporated into the conservation management plans prior to restoration works. This will ensure compatible and sustainable restoration of historic buildings, not only in South Africa, but around the world. The heritage materials for the two oldest buildings in the Western Cape were made of hydraulic lime-based mortars, seashells, and uniform and well-graded sand. Less than 5% of the materials showed no traces of a binder. The restored areas were restored with cement-based materials. The affordable standard methodology for characterising original heritage cementing materials involved the sample collection that represents the majority of the building, sample preparation, detailed visual investigation and cohesion test, as well as hydraulicity and cementation indices analysis to determine the type of binder. These tests were concluded to be convenient, easy to conduct and cost-effective.

Research in art conservation has been developed from the early 1950s, giving a significant contribution to the conservation-restoration of cultural heritage artefacts. In fact, only through a profound knowledge about the nature and conditions of constituent materials, suitable decisions on the conservation and restoration measures can thus be adopted and preservation practices enhanced. The study of ancient artworks is particularly challenging as they can be considered as heterogeneous and multilayered systems where numerous interactions between the different components as well as degradation and ageing phenomena take place. However, difficulties to physically separate the different layers due to their thickness (1-200 µm) can result in the inaccurate attribution of the identified compounds to a specific layer. Therefore, details can only be analysed when the sample preparation method leaves the layer structure intact, as for example the preparation of embedding cross sections in synthetic resins. Hence, spatially resolved analytical techniques are required not only to exactly characterize the nature of the compounds but also to obtain precise chemical and physical information about ongoing changes. This thesis focuses on the application of FTIR microspectroscopic techniques for cultural heritage materials. The first section is aimed at introducing the use of FTIR microscopy in conservation science with a particular attention to the sampling criteria and sample preparation methods. The second section is aimed at evaluating and validating the use of different FTIR microscopic analytical methods applied to the study of different art conservation issues which may be encountered dealing with cultural heritage artefacts: the characterisation of the artistic execution technique (chapter II-1), the studies on degradation phenomena (chapter II-2) and finally the evaluation of protective treatments (chapter II-3). The third and last section is divided into three chapters which underline recent developments in FTIR spectroscopy for the characterisation of paint cross sections and in particular thin organic layers: a newly developed preparation method with embedding systems in infrared transparent salts (chapter III-1), the new opportunities offered by macro-ATR imaging spectroscopy (chapter III-2) and the possibilities achieved with the different FTIR microspectroscopic techniques nowadays available (chapter III-3). In chapter II-1, FTIR microspectroscopy as molecular analysis, is presented in an integrated approach with other analytical techniques. The proposed sequence is optimized in function of the limited quantity of sample available and this methodology permits to identify the painting materials and characterise the adopted execution technique and state of conservation. Chapter II-2 describes the characterisation of the degradation products with FTIR microscopy since the investigation on the ageing processes encountered in old artefacts represents one of the most important issues in conservation research. Metal carboxylates resulting from the interaction between pigments and binding media are characterized using synthesised metal palmitates and their production is detected on copper-, zinc-, manganese- and lead- (associated with lead carbonate) based pigments dispersed either in oil or egg tempera. Moreover, significant effects seem to be obtained with iron and cobalt (acceleration of the triglycerides hydrolysis). For the first time on sienna and umber paints, manganese carboxylates are also observed. Finally in chapter II-3, FTIR microscopy is combined with further elemental analyses to characterise and estimate the performances and stability of newly developed treatments, which should better fit conservation-restoration problems. In the second part, in chapter III-1, an innovative embedding system in potassium bromide is reported focusing on the characterisation and localisation of organic substances in cross sections. Not only the identification but also the distribution of proteinaceous, lipidic or resinaceous materials, are evidenced directly on different paint cross sections, especially in thin layers of the order of 10 µm. Chapter III-2 describes the use of a conventional diamond ATR accessory coupled with a focal plane array to obtain chemical images of multi-layered paint cross sections. A rapid and simple identification of the different compounds is achieved without the use of any infrared microscope objectives. Finally, the latest FTIR techniques available are highlighted in chapter III-3 in a comparative study for the characterisation of paint cross sections. Results in terms of spatial resolution, data quality and chemical information obtained are presented and in particular, a new FTIR microscope equipped with a linear array detector, which permits reducing the spatial resolution limit to approximately 5 µm, provides very promising results and may represent a good alternative to either mapping or imaging systems.

Research in art conservation has been developed from the early 1950s, giving a significant contribution to the conservation-restoration of cultural heritage artefacts. In fact, only through a profound knowledge about the nature and conditions of constituent materials, suitable decisions on the conservation and restoration measures can thus be adopted and preservation practices enhanced. The study of ancient artworks is particularly challenging as they can be considered as heterogeneous and multilayered systems where numerous interactions between the different components as well as degradation and ageing phenomena take place. However, difficulties to physically separate the different layers due to their thickness (1-200 µm) can result in the inaccurate attribution of the identified compounds to a specific layer. Therefore, details can only be analysed when the sample preparation method leaves the layer structure intact, as for example the preparation of embedding cross sections in synthetic resins. Hence, spatially resolved analytical techniques are required not only to exactly characterize the nature of the compounds but also to obtain precise chemical and physical information about ongoing changes. This thesis focuses on the application of FTIR microspectroscopic techniques for cultural heritage materials. The first section is aimed at introducing the use of FTIR microscopy in conservation science with a particular attention to the sampling criteria and sample preparation methods. The second section is aimed at evaluating and validating the use of different FTIR microscopic analytical methods applied to the study of different art conservation issues which may be encountered dealing with cultural heritage artefacts: the characterisation of the artistic execution technique (chapter II-1), the studies on degradation phenomena (chapter II-2) and finally the evaluation of protective treatments (chapter II-3). The third and last section is divided into three chapters which underline recent developments in FTIR spectroscopy for the characterisation of paint cross sections and in particular thin organic layers: a newly developed preparation method with embedding systems in infrared transparent salts (chapter III-1), the new opportunities offered by macro-ATR imaging spectroscopy (chapter III-2) and the possibilities achieved with the different FTIR microspectroscopic techniques nowadays available (chapter III-3). In chapter II-1, FTIR microspectroscopy as molecular analysis, is presented in an integrated approach with other analytical techniques. The proposed sequence is optimized in function of the limited quantity of sample available and this methodology permits to identify the painting materials and characterise the adopted execution technique and state of conservation. Chapter II-2 describes the characterisation of the degradation products with FTIR microscopy since the investigation on the ageing processes encountered in old artefacts represents one of the most important issues in conservation research. Metal carboxylates resulting from the interaction between pigments and binding media are characterized using synthesised metal palmitates and their production is detected on copper-, zinc-, manganese- and lead- (associated with lead carbonate) based pigments dispersed either in oil or egg tempera. Moreover, significant effects seem to be obtained with iron and cobalt (acceleration of the triglycerides hydrolysis). For the first time on sienna and umber paints, manganese carboxylates are also observed. Finally in chapter II-3, FTIR microscopy is combined with further elemental analyses to characterise and estimate the performances and stability of newly developed treatments, which should better fit conservation-restoration problems. In the second part, in chapter III-1, an innovative embedding system in potassium bromide is reported focusing on the characterisation and localisation of organic substances in cross sections. Not only the identification but also the distribution of proteinaceous, lipidic or resinaceous materials, are evidenced directly on different paint cross sections, especially in thin layers of the order of 10 µm. Chapter III-2 describes the use of a conventional diamond ATR accessory coupled with a focal plane array to obtain chemical images of multi-layered paint cross sections. A rapid and simple identification of the different compounds is achieved without the use of any infrared microscope objectives. Finally, the latest FTIR techniques available are highlighted in chapter III-3 in a comparative study for the characterisation of paint cross sections. Results in terms of spatial resolution, data quality and chemical information obtained are presented and in particular, a new FTIR microscope equipped with a linear array detector, which permits reducing the spatial resolution limit to approximately 5 µm, provides very promising results and may represent a good alternative to either mapping or imaging systems.

This thesis in applied physics analyzes and solves problems regarding destructive and protective atmospheric microclimates in order to slow down the deterioration of indoor cultural heritage materials. Fresh approaches to two longstanding areas of concern are made in laboratory studies with a view to future field testing and evaluation by heritage conservation practitioners and museum display case manufacturers. Methods used for observing and analysing materials are macrophotography, optical microscopy, metallography, image analysis, X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Structural engineering methods comprise geometric surveys and compression and deflection tests. Airtightness measurement techniques were tracer gas decay and pressure decay. Investigations into the corrosion of lead by oak-emitted volatile organic compounds (VOCs) revealed the presence of a rarely reported crystalline phase which was confirmed to be associated with modern oak. The morphology and composition of the observed products of corrosion were almost identical to those found in field environments, but differed in specific ways to prior laboratory studies which used synthetic or oak-emitted VOCs. Five novel surface protection treatments using materials derived from ethanolic solutions of high molecular weight carboxylic acids (CH3(CH2)n-2COOH; n = 10, 12, 14, 16 or 18) were tested atmospherically for five years. Hexadecanoic (n = 16) and octadecanoic acid (n = 18) treatments inhibited corrosion of lead exposed to oak VOCs by up to ≈60%. These effective treatment materials showed lamellar morphologies similar to those made from aqueous solutions of lower molecular weight carboxylic acids (n = 10 or 11). In contrast, two materials with non-lamellar morphologies made from ethanolic decanoic acid (n = 10) and tetradecanoic acid (n = 14) were found to increase corrosion. Inspections of industry-made medium-sized (≈1 m3 ) museum display cases with doors located systematic leaks in sorbent compartments, around exhibit compartment doors and in ceilings: providing vertical leakage circuits driven by stack pressures (˜0.1 Pa). A walk-in test chamber with a custom-designed tracer gas and environmental monitoring system was made to evaluate three devices for passively controlling airtightness on a pair of display cases. Airtightness of the cases was increased by 7 to 13 times. Despite remaining leaks in the ceilings, the cases reached or went beyond the microbarometric limit; due to new pressure-proofed sorbent compartments and novel convex gaskets for the compliant unframed exhibit compartment doors; solving leakage caused by restorative forces imposed by gaskets. The greatest airtightness (0.013±0.004 air exchanges daily) was achieved by a case retrofitted with a pair of high compliance bellows (Δ±2 Pa) with high conductance pipework, while being subjected to temperature cycling (Δ+2°C daily) and natural barometric pressure fluctuations. A formula derived from Ohm’s Law to evaluate the minimum required airway resistance of gaps in display cases was proposed as a new way to calculate, and then measure, the capability of a case to have its airtightness increased by installing bellows.

Els estudis que es presenten en aquesta tesi doctoral se centren en l’aplicació i millora de metodologies analítiques existents, relativament senzilles, i el desenvolupament de nous procediments que poden utilitzar-se per a l’estudi de materials del Patrimoni Cultural. La posada en pràctica i la modelització de la resposta analítica de les tècniques espectroscòpiques utilitzades en aquest treball s’ha dut a terme mitjançant l’anàlisi de materials antics de diferent tipus, començant amb materials de composició relativament senzilla com ara aliatges metàl·lics i passant, gradualment, a l’estudi de materials amb matrius més complexes tals com pigments minerals, papers i tintes. Els resultats obtinguts són de notable interès per a la conservació d’aquests materials, aspecte rellevant donada la seva fragilitat i elevat potencial d’alterabilitat. En aquest sentit, en primer lloc es va fer un estudi exhaustiu de monedes antigues de diversa cronologia, mitjançant l’ús de la fluorescència de raigs X per dispersió d’energies (EDXRF). Els resultats de les anàlisis van permetre determinar no només la composició química elemental de les monedes i donar resposta a algunes de les qüestions plantejades pels historiadors, sinó que també van permetre optimitzar al màxim les condicions experimentals de les anàlisis i fixar els límits de quantificació per aquest tipus de matrius. En segon lloc, es va dur a terme un estudi multi-espectroscòpic de pintures a l’oli sobre suports metàl·lics (coure i llautó) de diversa cronologia (una del segle XVII i l’altra de finals del segle XVIII). Els resultats de les anàlisis van esser útils, per una banda, per establir la distribució elemental en superfície a partir d’un mètode quantitatiu d’anàlisis EDXRF desenvolupat específicament per aquest tipus d’obres d’art i, per l’altra, identificar els compostos utilitzats en l’elaboració de les pintures (pigments i aglutinants) a partir de la utilització de difracció de raigs X (XRD) i espectroscòpies Raman (RS) i infraroja per transformada de Fourier (FTIR). En tercer lloc, es va realitzar un ampli estudi analític (tot emprant EDXRF, RS i FTIR) de cromolitografies del segle XIX amb l’objectiu de caracteritzar el material de suport i identificar-ne les tintes utilitzades per a la seva coloració. A més de les conclusions històriques, els resultats de les anàlisis posaven de manifest la necessitat de dur a terme una aproximació multi-analítica per a una complerta caracterització dels materials estudiats. Finalment, en quart lloc es va dur a terme un estudi arqueomètric (emprant EDXRF, XRD, FTIR, microscòpia òptica de polarització (PLM) i microscòpia electrònica de centelleig (SEM-EDS)) de pintura mural d’època clàssica. Els resultats de les anàlisis van permetre obtenir informació relativa a la naturalesa dels pigments utilitzats i la seva possible procedència per una banda, i per l’altra caracteritzar els materials de suport, descriure la qualitat dels estucs i determinar si seguien els models descrits pels autors clàssics.
Los estudios que se presentan en esta tesis doctoral se centran en la aplicación y mejora de metodologías analíticas existentes, relativamente sencillas, y el desarrollo de nuevos procedimientos que pueden ser utilizados para el estudio de materiales del Patrimonio Cultural. La puesta a punto y la modelización de la respuesta analítica de las técnicas espectroscópicas utilizadas se ha llevado a cabo mediante el análisis de materiales antiguos de distinta índole, empezando con materiales de composición sencilla tales como metales y pasando paulatinamente al estudio de materiales con matrices más complejas (pigmentos minerales, papeles y tintas). Los resultados obtenidos son de notable interés para la conservación de dichos materiales, aspecto relevante dada su fragilidad y elevado potencial de alterabilidad. De este modo, en primer lugar se hizo un estudio exhaustivo de monedas antiguas de diversa cronología mediante el uso de la fluorescencia de rayos X por dispersión de energías (EDXRF). Los resultados de los análisis permitieron determinar no solo la composición química elemental de las monedas y dar respuesta a algunos de los problemas planteados por los historiadores, sino que también permitieron optimizar al máximo las condiciones experimentales de los análisis y fijar los limites de cuantificación para este tipo de matrices. En segundo lugar se llevó a cabo un estudio multi-espectroscópico de pintura al óleo sobre cobre de dos ejemplares de distinta cronología (uno del siglo XVII y otro de finales del siglo XVIII). Los resultados de los análisis han sido útiles, por un lado, para establecer la distribución elemental en superficie a partir de un método semi-cuantitativo de análisis EDXRF desarrollado especialmente para este tipo de obras y, por el otro, identificar los compuestos empleados en la elaboración de las pinturas (pigmentos y aglutinantes entre otros) a partir de la utilización de la difracción de rayos X (XRD) y espectroscopías Raman (RS) e infrarroja por transformada de Fourier (FTIR). En tercer lugar se realizó un amplio estudio analítico (utilizando EDXRF, XRD, RS y FTIR) de papeles del siglo XIX con el fin de caracterizar el soporte e identificar las tintas empleadas. Además de las conclusiones históricas, los resultados de los análisis ponen de manifiesto la necesidad de un estudio multi-analítico para una completa caracterización de los materiales estudiados. Por último, en cuarto lugar se llevó a cabo estudio arqueométrico completo (empleando EDXRF, XRD, FTIR, microscopía óptica de polarización (PLM) y microscopía óptica de barrido (SEM-EDS)) de pintura mural de época clásica. Los resultados de los análisis permitieron obtener información relativa, por un lado, a la naturaleza de los pigmentos utilizados y su posible procedencia y, por otro lado, caracterizar los materiales de soporte, describir la calidad de los estucos y determinar si siguen los modelos propuesto por los autores clásicos.
The research presented in this thesis is focused on the application and improvement of analytical existing procedures and the development of new methodologies that can be employed for the study of Cultural Heritage materials. The starting up and modelling of the analytical response was fulfilled by the analysis of different type of ancient materials, starting with materials of relatively simply composition such as metallic alloys, and going through the analysis of materials with more complexes matrices, such as mineral pigments, ancient documents and inks). The obtained results are of considerable interest for the conservation of these materials, as they are usually fragile and have a high potential of alterability. In this sense, the first analytical experience was carried out on metallic artefacts. The study involved the characterization of ancient coins from diverse chronology by means of non-destructive energy dispersive X-ray fluorescence (EDXRF). The results of the analysis allowed determining the elemental composition of the coins and answer some of the questions presented by the historians. Moreover the optimization of the experimental parameters and quantification limits (LOQ) were carefully determined for this kind of matrices. In a second stage, a multi-spectroscopic study of two “oil on copper” paintings from different chronology (seventeenth and nineteenth centuries respectively) was carried out. The results allowed establishing, on one hand, the pigment mass distribution along the painting surfaces by using a semi-quantitative EDXRF method developed specifically for such kind of artworks. On the other hand, identifying the compounds employed to elaborate the paintings (pigments and binders amongst others) by using XRD, RS and FTIR spectroscopies. In a third stage, a full analytical approach of chromolithographs from the nineteenth century was done by using EDXRF, XRD, RS and FTIR instrumentation. The study was carried out in order to characterize the supporting material and identify the employed inks for colouring the lithographs. Apart of the historical explanations, results of the analysis highlighted the necessity of having a multi-analytical approximation for the proper characterization of such kind of materials. Finally, a complete archaeometric study of ancient wall-paintings was accomplished by employing EDXRF, XRD, FTIR, PLM and SEM-EDS. The results of the analytical campaign allowed not only obtaining information related to the nature of the employed pigments and their possible provenance but also characterizing the supporting materials (including their mineralogical and textural description), and determining whether they follow or not the procedures explained in the classical textual sources.

The common thread of the PhD project is the development of strategies, based, primarily, on dynamic electroanalytical techniques, for investigating and characterizing different types of substrates of historic/artistic interest. The use of electrochemical apparatuses and approaches was done, where possible, in the least invasive way, to characterize metal-based materials; from the other side to propose new systems and approaches to study materials, which can suffer from contact with liquid electrolytes. The research on copper natural patinas was applied, in a first part, to relatively easy systems composed by primary patina, essentially made of cuprite. Here, ancient coins were studied by the voltammetry of immobilized particles (VIMP) technique simply by pressing a graphite pencil on their surface, thus resulting in an essentially non-destructive sampling, useful characteristic for the study of cultural heritage materials. The new approach developed has revealed the existence of different corrosion patterns which are sensitive to the composition of the base metal, in particular to the presence of Zn. Voltammetric data suggests the possibility of establishing a chronological ordering of the coins and hence to add this multiple scan strategy to the existing electrochemical dating methods. A further step in the research activity was was to investigate copper-based materials in a more complex corrosion status (presence of primary cuprite together with brochantite). The goal was to study the effect of alternative, to classical and poorly environmentally safe, corrosion inhibitors. Specifically, decanoic acid (HC10) and its sodium salt (NaC10) have been considered here, as potential eco-friendly inhibitors. In a first part of the research activity, the interactions between Cu2+ and HC10 in water and 50% (v/v) E/W mixture was elucidated by a detailed analysis of the voltammetric responses. The results obtained proved useful to clarify some aspects of the mechanisms which could be involved when the corroded roof claddings are treated with the inhibitors and the stability of the coatings when the samples are immersed in synthetic acid rain. A second section of the study aimed at comparing the protective effects of HC10, NaC10 and the poorly environmentally safe benzotriazole (BTA) on bare copper and roof cladding samples. A third section of the study examines in detail the reactivity of the top layer and cross section of the roof cladding samples untreated and treated with HC10 and BTA. This study has been performed by using SECM to get information on the reactivity with high spatial resolution. The ability of the inhibitors to prevent further corrosion of the various layers of patina was assessed in aqueous media containing NO3-, SO42- and Cl-, which are characterized by different complexing ability towards copper ions. The research activity continued in the direction of investigating innovative strategies based on the use of microcapillary (MC) techniques. In particular, MCs filled with conductive hydrogels have been developed with the objective of applying it to study materials that suffer the contact with liquid solutions and metallic objects. Here, the properties of agarose hydrogel as medium to perform voltammetric measurements, using the electroactive redox probes and a Pt microdisk electrode were examined. The hydrogel containing the redox probe and various electrolytes are employed for MC contact measurements above platinum and gold substrates. To demonstrate the suitability of the above microprobe for more practical applications, proof-of-concept measurements were performed to characterize micro areas of metallic silver deposited on to the surface of a pencil graphite line deposited on a paper material. With the purpose to tailor the electrode surface or the content of MCs with more selective compounds, condconducting polymers, presenting intrinsic chiral activity, have been studied.

Natural hazards, such as earthquakes, can compromise the integrity of the cultural heritage with potentially devastating effects. The reduction of the seismic vulnerability of the cultural heritage constitutes a question of maximum importance especially in countries where vast cultural heritage combines with a medium or high seismic risk, such as in Italy. From the second half of the last century, the scientific community edited a number of important documents and charts for the conservation, reinforcement and restoration of the cultural heritage. The aim is to mitigate the seismic vulnerability of the cultural heritage. This research focused on high performance materials for applications aimed to structural and seismic protection of cultural heritage, with a special focus on historical masonry structures. In particular, the final aim is to define a self-diagnosis strategy for fibres, yarns and ties in view of efficient, non-invasive and reversible interventions on cultural heritage buildings. In order to set up the scene, the present thesis starts by introducing the reader to the seismic protection of cultural heritage thorough an extensive review on high performance materials, strengthening techniques and systems, taking care to highlight real world applications and limitations of their use. The second step of this work concerns in the mechanical and rheological characterization of high performance material fibres. The materials investigated are essentially Kevlar® 29 (para-aramid), Carbon and Silicon Carbide. To reach this goal, an extensive experimental testing campaign was conducted on fibres and yarns in accordance with specific protocols. A further step was defining appropriate damage indices for different materials, with a special focus on Kevlar® 29. Within the same research programme, a novel testing machine was also designed in cooperation with the Laboratory of Electronic Measurements of the Politecnico di Torino. A prototype-testing machine for dynamic testing on high resistance fibres was built using recycled materials and components. A distinctive feature of this machine is that it can apply to the sample any kind of dynamic excitation (random, impulse, harmonic etc.). A second testing campaign concerned the durability of Kevlar® 29 fibres, which are known to be sensitive to long-term exposure to UV radiation. Accordingly, for this campaign, the samples were artificially damaged by using UV lamps. The analysis of the resonance profiles allowed for the extraction of parameters such as the elastic moduli, quality factors, and non-linear coefficient for a set of fibres. In particular, non-linearity parameters derived from the Krylov-Bogoliubov method demonstrated to be consistent with the damage affecting the fibres. The final chapter of the dissertation concerns a new concept for a tie endowed with self-diagnosis properties, which are obtained by integrating a low cost testing device into the tie model. The self-diagnosis properties system of existing structures has an important role in the preservation of the cultural heritage because the best therapy is preventive maintenance. Specifically, the para-aramid tie system proposed for the reinforcement of historic building constitutes a non-invasive, reversible and repeatable intervention, as required by the main guidelines on preservation of cultural heritage.

The Panamanian isthmus hosts two sites inscribed on the World Heritage List: the Archaeological site of Panama Viejo (XVI cent.) and the Fortresses of Portobelo and San Lorenzo (XVII-XVIII cent.). In order to support the conservation and valorisation of these places, in 2014 a collaboration work has been started among the Patronages of Panama Viejo and of Portobelo and San Lorenzo, the Italian CNR-ISAC and the Department of Physics and Earth Sciences of the University of Ferrara. Firstly, the project was focused on the characterization of rocks belonging to the masonries, in conjunction with the evaluation of their state of conservation and damage estimation in relation with the environmental impact. Furthermore, potential quarries of raw material supply have been identified and sampled. Therefore, after a survey and sampling campaign, specimens underwent the following analyses: stereomicroscope, PLM, XRPD, SEM-EDX, XRF, MIP and IC, highlighting at Panamá Viejo masonries mainly composed of polygenic breccias, tuffites, basaltic andesites, rhyolites and sporadic rhyodacites, while outcrops of breccias and andesites were identified. Considering Portobelo fortifications, coral limestones and sandstones have been identified as principal construction materials; while basaltic andesite has been observed only at Fuerte de San Fernando, where an outcrop of this material was present. Finally, at Fort San Lorenzo, tuffites and grainstones have been detected in the masonries and possible quarries of both have been found. Concerning the state of conservation, the most diffused deterioration phenomena are due to biological growth, exfoliation and detachment, disintegration, salt encrustations and chromatic alteration. Successively, in order to determine the environmental context, a selection of monitoring stations, recording climate parameters (near-surface air temperature, relative humidity and rainfall amount), have been chosen near the sites among national Panamanian networks. Besides, the same parameters were collected from two climate models, both from historical simulations and future scenarios: EC-Earth, 25 km of resolution, and Arpege 50 km of resolution, and compared with the monitored records. Utilizing environmental data obtained and applying specific damage functions it was possible to assess the deterioration phenomena occurring on heritage materials, as surface recession, cycles of salts transition and biomass accumulation. Considering the first one, it was utilized Lipfert function modified, related to the karst effect. The area of Portobelo and San Lorenzo showed a higher surface recession, especially considering the data extracted from EC-Earth experiment, both for the past and the future situation. In consideration of the salts cycles of dissolution and crystallization, halite has been elected as a priority phase of investigation, since sodium and chloride resulted ones of the most abundant ions in the samples, detected in all sites, also taking into account their proximity to the sea. The past situation (1979-2008) highlighted that the higher frequency of halite transition cycles is recorded during the dry season (November/December to April/ May). In general, Portobelo results the less interested by this phenomenon, while the area near San Lorenzo seems to be the most affected. In order to estimate the biomass accumulation on hard acid stones, the function developed by Gomez-Bolea et al. (2012) was applied. The highest yearly biomass values are recorded at Portobelo, both in the past and future. In conclusion, the obtained results contribute significantly to the formulation of guidelines and development of strategies for current and future preservation of the sites, and represent a fundamental knowledge for further related analysis, in order to increase the awareness of the possible risks connected with the climate change impact on Cultural Heritage.
L'istmo di Panama ospita due siti iscritti alla World Heritage List, ossia il sito Archeologico di Panama Viejo (XVI sec.) e i Fortini di Portobelo e San Lorenzo (XVII-XVIII sec.). Al fine di supportare la conservazione e la valorizzazione di questi luoghi, è stato avviato un lavoro di collaborazione tra i Patronati di Panama Viejo e di Portobelo e San Lorenzo, il CNR-ISAC e il Dipartimento di Fisica e Scienze della Terra dell'Università di Ferrara. In primo luogo il progetto è stato focalizzato sulla caratterizzazione dei materiali lapidei naturali costituenti le murature, compresa la valutazione del loro stato di conservazione e dei fenomeni di degrado dovuti all'impatto ambientale. In aggiunta sono state identificate possibili cave di approvvigionamento dei materiali da costruzione. Pertanto, a seguito di una campagna di campionamento, i frammenti ottenuti sono stati sottoposti ad analisi per mezzo di stereomicroscopio, XRPD, SEM-EDX, XRF, MIP e IC. Queste hanno permesso di identificare brecce poligeniche, tufiti, andesiti basaltiche, rioliti e alcune riodaciti, come materiali impiegati nelle murature dei monumenti di Panamá Viejo; mentre sono stati individuati affioramenti di brecce e andesiti basaltiche. Considerando le fortificazioni di Portobelo, calcari corallini e arenarie sono i principali materiali costituenti le strutture murarie. Andesiti basaltiche sono state rinvenute solo a Fuerte de San Fernando, dove erano presenti anche in affioramento. Infine, presso Forte San Lorenzo, i materiali da costruzione impiegati sono tufiti e grainstone, delle quali sono state individuate anche possibili cave. Prendendo in considerazione lo stato di conservazione, i fenomeni di alterazione più diffusi sono ascrivibili a crescita biologica, esfoliazione e distacchi, disgregazione, incrostazioni saline ed alterazioni cromatiche. Successivamente, al fine di determinare il contesto ambientale, sono state selezionate delle stazioni di monitoraggio, appartenenti alla rete nazionale panamense, situate nei pressi dei siti oggetto di studio, che registrassero parametri climatici quali temperatura dell’aria, umidità relativa e pioggia. Gli stessi parametri sono stati estratti anche da simulazioni storiche e scenari futuri di due modelli climatici: EC-Earth, con risoluzione di 25 km, e Arpege, con risoluzione di 50 km, comparandoli con quelli ottenuti dalle centraline. Utilizzando i dati ambientali in specifiche funzioni di danno, è stato possibile valutare diverse morfologie di degrado come la recessione superficiale, cicli di transizioni saline e accumulo di biomassa. Riguardo alla prima, è stata utilizzata la funzione di Lipfert modificata, relativa all’effetto carsico. Questa ha permesso di rilevare una maggiore recessione nelle aree di Portobelo e San Lorenzo, specialmente considerando i dati di EC-Earth, sia per la situazione passata che futura. Considerando i cicli di dissoluzione e cristallizzazione dei sali, lo studio si è incentrato sulla halite, poiché sodio e cloro sono risultati essere gli ioni più abbondanti nei campioni di tutti i siti, essendo infatti tutte aree costiere marine. In generale, paragonando le condizioni passate e future, Portobelo risulta essere il meno interessato dal fenomeno, mentre l’area in prossimità di San Lorenzo la più soggetta. Al fine di stimare l’accumulo di biomassa su rocce acide, è stata impiegata la funzione messa a punto da Gomez-Bolea et al. (2012), rivelando valori di biomassa più elevati nella costa Nord, specialmente a Portobelo. In conclusione, i risultati ottenuti hanno permesso di contribuire significativamente alla futura formulazione di linee guida e nello sviluppo delle attuali e future strategie di preservazione dei siti, rappresentando una conoscenza fondamentale per studi successivi, al fine di incrementare la consapevolezza dei possibili rischi connessi all’impatto dei cambiamenti climatici sul patrimonio culturale.

Digitale oder digitalisierte Tonaufnahmen sind zunehmend gefragte, wichtige Quellen für die Wissenschaft und als Dokumente des kulturellen Erbes auch für eine breite Öffentlichkeit von großem Interesse. Die Online-Bereitstellung frei zugänglicher Audiodokumente als Open Cultural Heritage erweist sich für Bibliotheken und Archive in der Praxis jedoch häufig als schwierig. Der Beitrag umreißt die besonderen Herausforderungen bei der Digitalisierung und Bereitstellung von Tondokumenten und skizziert – auch anhand von Praxisbeispielen – verschiedene Wege, auf denen Sammlungen den Anforderungen von Open Science gerecht werden können.
Digital or digitized sound recordings are increasingly demanded, and important sources for science. As documents of cultural heritage, they are also of great interest to the general public. However, providing freely accessible audio documents online as Open Cultural Heritage is often difficult for libraries and archives in practice. The article sketches the specific challenges of digitizing and publishing sound documents and outlines – also on the basis of practical examples – different ways in which collections can meet the requirements of open science.

Many historical objects have coatings or varnish layers on the surface. In order to determine their conservation and historical contextualization is necessary to know its origin, why they were applied, the application technique and how they aged. In this context we found that one kind of material used is diterpenic resin obtained from species of the Pinaceae family. A search in historical sources from 9th to 19th centuries was performed in order to know how Pinaceae resin was used during history. It has been observed that resins from certain Pinaceae species such as Abies alba Mill. or Larix decidua Mill. were mainly applied in valuable objects. On the other hand, Pinus species were mainly used in daily objects without artistic merit. Moreover, it is also noted that, generally, coatings made from Pinaceae species resin include also other resins, essential oils, drying oils, etc. However, the analytical data obtained from varnishes and coatings of historical objects from our geographical environment, demonstrate that Pinus resin was used in a wider range of objects than the ones mentioned in consulted historical sources. The analysis of varnish and coating layers is very intricate. Besides the complexity of its composition, these layers are very thin, <20 µm, and they are on the surface so many interferences can be found like deposition products or even remains of biological activity. This work is focused on the study of main compounds of Pinaceae species resins used in varnishes and coatings. Particularly, it is centred in resin from Pinus genus species: its aging processes and its markers in FTIR and Raman spectra in order to detect the oxidation degree of this material. The main analytical techniques used are vibrational spectroscopies µRaman and µFTIR. While these techniques have some limitations, particularly its low sensitivity, they provide information from a wide range of molecular and intermolecular bonds. Additionally, analysis are fast, the cost is moderate and have a reduced environmental impact, since waste generated is very low. Obtained results have been used for the analysis of coatings and varnishes from historical objects. These analysis have been performed with optimized sample preparation methods and using complementary analytical techniques such as optical microscopy, scanning electron microscopy (SEM-EDX) and analytical techniques with synchrotron sources for small heterogeneous samples with complex structure (µSR-FTIR in Diamond Synchrotron Light Source, Oxfordshire and µSR-XRD Synchrotron ALBA-CELLS, Barcelona).
A la superfície de molts objectes d’interès històric s ’hi troben capes de vernís o recobriments dels quals, per la seva conservació i contextualització històrica, és necessari conèixer el seu origen, la raó per la qual van ser aplicats, la tècnica d’aplicació i com els ha afectat el pas del temps. En aquest context ens trobem que un dels materials que ha estat àmpliament utilitzat és la resina diterpènica obtinguda d’espècies de la família Pinaceae. S’ha dut a terme una cerca en tractats i manuscrits d’entre els segles IX i XIX per veure quin impacte tenia el seu ús i com s ’aplicaven històricament. S'ha observat que resines d’espècies com ara Abies alba Mill. o Larix decidua Mill. eren principalment reservades per vernissos i recobriments d'objectes de valor artístic. En aquests tractats també es pot veure que l’ús principal de la resina extreta d’espècies de Pinus era per vernissos i recobriments d'objectes d’ús quotidià i, generalment, de poc valor artístic. De la mateixa manera, s'observa que habitualment els recobriments fets amb resina de Pinaceae contenien també altres tipus de resines, olis essencials, olis assecants, etc. No obstant això, les dades analítiques obtingudes d’objectes artístics de diferents èpoques del nostre entorn geogràfic, van indicant que la resina de Pinus era més àmpliament emprada del que es descriu a les fonts històriques consultades. La complexitat de l’anàlisi d’aquestes capes de vernís o recobriments, més enllà de la complexitat de la seva composició, és que acostumen a trobarse en capes de molt poc gruix, <20 μm, i que es tan en contacte amb l’ambient, i per tant s ’hi pot trobar també deposició de pols i, fins i tot, res idus d’activitat biològica. Aquest treball es centra en l’estudi dels components principals de les resines de la família Pinaceae utilitzades en vernissos i recobriments. Concretament en les espècies del gènere Pinus , els proces s os d’envelliment i l’obtenció de marcadors als espectres de FTIR i Raman per detectar-ne el grau d’oxidació del material. Les tècniques d’anàlisi principals han estat les espectroscòpies vibracionals μFTIR i μRaman. Si bé aquestes tècniques presenten algunes limitacions, especialment pel que fa a la sensibilitat, permeten obtenir informació d’un ampli ventall d’enllaços moleculars i intermoleculars. A més, les anàlisis són ràpides, el seu cost és relativament baix i tenen un reduït impacte mediambiental, ja que la generació de residus és gairebé nul·la. Els resultats obtinguts s ’han utilitzat per l’anàlisi de recobriments d’objectes d’interès històrico-artístic. Per dur a terme aquestes anàlisis s ’han optimitzat mètodes de preparació de mostra i utilitzat tècniques analítiques complementàries, com ara la microscòpia òptica i la microscòpia electrònics de ras treig (SEM-EDX) i l’ús de tècniques associades a la llum sincrotró quan la quantitat, heterogeneïtat i estructura de les mostres ho han fet necessari (μSR-FTIR al Sincrotró Diamond Light Source, Oxfordshire i μSR-XRD al Sincrotró ALBA-CELLS, Barcelona).
En la superficie de muchos objetos de interés histórico se encuentran capas de barniz o recubrimientos de los que, por su conservación y contextualización histórica, es necesario conocer el origen, por qué motivo fueron aplicados, la técnica de aplicación y cómo les ha afectado el paso del tiempo. En este contexto nos encontramos que uno de los tipos de materiales utilizados son las resinas diterpénicas obtenidas de especies de la familia Pinaceae. Se ha llevado a cabo una búsqueda en tratados y manuscritos de entre los siglos IX y XIX para conocer sus usos y cómo se han aplicado a lo largo de la historia. Se ha observado que resinas de ciertas especies de Pinaceae como Abies alba Mill. o Larix decidua Mill. eran principalmente reservadas a los objetos de valor artístico. En estos tratados también se comprueba que las resinas de las especies de Pinus se usaban principalmente en objetos de cotidianos y generalmente de poco valor artístico. Además se observa que, generalmente, los barnices hechos a partir de resinas de especies de Pinaceae suelen incluir también otras resinas, aceites esenciales, aceites secantes, etc. Sin embargo, los datos analíticos de los barnices y recubrimientos de objetos artísticos de diferentes épocas de nuestro entorno geográfico, van indicando que la resina de Pinus era más ampliamente empleada de lo que se describe en las fuentes históricas consultadas. La dificultad del análisis de estas capas de barniz o recubrimientos, además de la complejidad de su composición, reside en que suelen encontrarse en capas de muy poco grosor, <20 μm, y que están en contacto con el ambiente, de modo que en la superficie se puede encontrar también deposición de polvo e, incluso, residuos de actividad biológica. Este trabajo se centra en el estudio de los componentes principales de las resinas de la familia Pinaceae usadas en barnices y recubrimientos. Concretamente se centra en la resina de las especies del género Pinus, sus procesos de envejecimiento y la obtención de marcadores en los espectros de FTIR y Raman para detectar el grado de oxidación del material. Las técnicas analíticas principales han sido las espectroscopias vibracionales μFTIR y μRaman. Si bien estas técnicas presentan algunas limitaciones, especialmente en cuanto a la baja sensibilidad, permiten obtener información de un amplio abanico de enlaces moleculares e intermoleculares. Además, los análisis son rápidos, su coste es relativamente bajo y tienen un reducido impacto medioambiental, dado que la generación de residuos es prácticamente nula. Los resultados obtenidos se han utilizado para el análisis de recubrimientos de objetos de interés histórico-artístico. Para llevar a cabo estos análisis se han optimizado los métodos de preparación de muestra y se han usado técnicas analíticas complementarias, como la microscopía óptica, la microscopía electrónica de barrido (SEM-EDX) y el uso de técnicas asociadas a la luz sincrotrón cuando la cantidad, heterogeneidad y estructura de las muestras lo han hecho necesario (μSR-FTIR en el Sincrotrón Diamond Light Source, Oxfordshire y μSR-XRD en el Sincrotrón ALBA-CELLS, Barcelona).

Doutoramento em Engenharia Civil
The risk of losing ancient construction systems is highly relevant in the whole Mediterranean region, but also in many other countries worldwide. The earthen heritage and the mixed construction systems with timber are decreasing very fast and being identified in lists of risk by UNESCO, ICOMOS and by many researchers all over the world. They represent a cultural value of the societies that is being neglected due to unbalanced development, demolitions, lack of knowledge, and guidelines for conservation, instead of the expected unique reason of decay due to natural agents or ageing. Although some conservation approaches have been successful, the results are still scarce and the mistakes continuously repeated imposing irreversible gaps in reading this relevant heritage, mainly in urban areas. This entails questions about the approach to protection, conservation, and the reasons behind such disseminated failure in these objectives. The earthen architecture shows precisely the difficulties in the establishment of a strategy able to successfully achieve the goal of preserving its cultural value. This needs continuous research and ability to communicate the best conservation strategy as just one of the steps of a balanced framework. This investigation aims to discover reasons for failure of conservation strategies involving the traditional construction systems, valuing the case of adobe architecture; to give significance to traditional construction systems as a cultural value to protect and preserve; to propose conservation research areas necessary in a framework of integrated conservation of built heritage, involving the specific case of adobe buildings. The research methodology of this investigation is based mostly on qualitative methods and a case study about adobe construction system, its evolution since the 19th century until the middle of 20th century, and its interaction with architecture. The case study was used to address the main identified gaps of research needed to proceed with an integrated conservation and protection approach of adobe heritage in Portugal. A combination of sources was used following a multi-method approach: in situ surveys, collection of archive files (drawings, written documents and photos), published literature, published and unpublished reports from international organisations, photographic reports, open interviews, and laboratory tests. The first analyses show evidence of multiple causes of failure for the support of conservation strategies. The most important is the lack of a long-term integrated strategy within a recognized and supported framework. Secondly, the continuity of shortcomings is expressed in inadequate choices at several levels of decision-making, absence of measures of maintenance and conservation. Thirdly, the lack of knowledge about the adobe traditional construction system, its evolution and wide interaction with architecture, the approach to the present standards of comfort, and finally, the problem of waterproof barrier and salt’s effects are the main causes of failure in the promotion of adobe conservation strategies. This research recommends the use of the construction system as a cultural value to guarantee the longevity of traditional building heritage, supported by research. It also stresses the importance of understanding the difficulties of application of conservation strategies, looking to a wider international area to better understand the reasons behind causes and eventual successes. It proposes an interpretation of evolution of the adobe construction system and identifies the main defects, both of which should constitute the base of knowledge of any conservation strategy. Finally, considering an integrated framework of conservation strategy, an approach is recommended that integrates key issues of awareness for heritage and research. The specific case study of adobe construction emphasized three main approach areas: the vernacular architecture for public awareness; thermal and comfort issues for protection strategy; and finally, the waterproof barrier with diatomaceous earth, its role in the decrease of salt’s effects and as an effective barrier, for the use of research to solve technical problems of earthen construction.
O risco de perder sistemas de construtivos antigos é altamente relevante em toda a região do Mediterrâneo, mas também em muitos outros países do mundo. O Património de terra e os sistemas construtivos mistos com madeira estão a decrescer rapidamente e são alvo de propostas para integrarem listas de Risco pela UNESCO, ICOMOS e com alertas de vários investigadores de todo o mundo. Estes sistemas, representam um valor cultural das sociedades, que está a ser negligenciado devido ao desenvolvimento desequilibrado, às demolições, à falta de conhecimento, e à falta de diretrizes para a conservação, em vez de a expectável única razão, de deterioração devido aos agentes naturais ou ao seu próprio envelhecimento. Embora algumas experiências de Conservação tenham sido bem sucedidas, os resultados ainda são escassos e os erros continuamente repetidos, impondo lacunas irreversíveis na leitura deste Património relevante, principalmente em áreas urbanas. Isto levanta questões sobre a abordagem à proteção, à conservação, e às razões que estão por trás de tão disseminada falha nos objetivos. A Arquitectura de Terra sofre precisamente destas dificuldades no estabelecimento de uma estratégia capaz de alcançar com sucesso o objetivo de preservar o seu Valor Cultural. O que requer uma investigação contínua e capacidade de comunicar a melhor estratégia de conservação capaz de alcançar com sucesso a compatibilização para a preservação do seu valor cultural, como apenas uma das etapas de um enquadramento equilibrado. Esta investigação tem como objetivo: descobrir as razões subjacentes ao fracasso de estratégias de conservação; investigar os sistemas de construção tradicionais, valorizando o caso da arquitetura de adobe; estudar a significância dos sistemas construtivos tradicionais como valores culturais a proteger e preservar; propor áreas de pesquisa de conservação dentro de um quadro de Conservação Integrada do Património construído, envolvendo o caso específico dos edifícios de adobe. As primeiras análises mostram evidências de múltiplas causas de fracasso para o apoio de medidas de conservação. O que mais se destaca é a falta de uma estratégia integrada de longo prazo, num programa reconhecido e apoiado. Em segundo lugar, a continuidade das deficiências é expressa nas escolhas inadequadas em vários níveis da tomada de decisão, a ausência de medidas de manutenção e conservação. Em terceiro lugar, a falta de conhecimento sobre os sistemas construtivos tradicionais (de adobe), sua evolução e ampla interação com a arquitetura, a abordagem sobre compatibilização dos atuais padrões de conforto com o valor cultural, e, finalmente, o problema particular do corte hídrico e controlo da ação dos sais no edificado antigo, são causas de falha nas estratégias de conservação de adobe, por falta de informação e de investigação. Esta pesquisa recomenda o reconhecimento do sistema construtivo como um valor cultural, para garantir a longevidade do Património construído tradicional, apoiado na investigação. Aborda as dificuldades de aplicação de estratégias de conservação, a nível internacional para melhor compreender as razões de sucesso ou fracasso. Propõe uma interpretação da evolução do sistema construtivo de adobe e identifica os principais defeitos, para apoiar a base de conhecimento de estratégias de conservação. Por fim, considerando o âmbito de uma Conservação Integrada recomenda uma abordagem que integre questões-chave de sensibilização para o património e investigação. O caso de estudo de construção de adobe enfatiza três destas áreas: a ligação entre a arquitetura vernacular e a arquitetura, para sensibilização do público; os problemas de compatibilidade com o conforto, para estratégia de proteção; e finalmente, o efeito da diatomite em barreiras de corte hídrico e aos sais, para apoio aos problemas técnicos de conservação do Património de Terra.
FCT - SFRH/BPD/113053/2015

Pas de résumé en français
One of the new challenges of conservation science is the development of field instrumentation to analyze works of art. In order to get the most information on the material, it is often necessary to perform complementary analyses by juggling different analytical techniques. This time-consuming drawback involves a difficulty to analyze the artwork on the same spot of the surface. However, some of spectroscopies have in common to use the same laser as excitation source and the collection of the emitted signal could be recorded by the same spectrometer. In this spirit, the aim of this research project is the development of a hybrid system in laboratory grouping together three analytical techniques (LIBS, LIF and Raman spectroscopy) in a single instrument. The relevance for combining these three spectroscopies is to identify a material (molecular and elemental analysis) without any preliminary preparation, regardless of its organic or inorganic nature, on the surface and in depth, without any surrouding light interference thanks to time-resolution. Such instrumentation would allow to characterize different materials from cultural heritage such as copper corrosion products and wall paintings organized in stratigraphic layers which are the example of applications in this work. A complete study on LIBS-LIF-Raman hybrid was carried out from conception to instrumental achievement, as well as automatic control to data fusion processings in order to elaborate a strategy of analysis according to the material and to be able to address conservation issues

This research indicates the scale of unknown archaeological fabric that is uncovered during the repair, alteration or development of heritage buildings, and the extent to which this fabric is incorrectly managed or disposed of without record. To understand why this occurs, this thesis analyses information from interviews with 100 people living in heritage buildings in three English towns. It shows that, although people are deeply concerned about the importance of heritage, found archaeological fabric is often disposed of without record or altered into new material form in response to the emotional, psychological and physical needs of those living and working in heritage buildings. Heritage values are often regarded as secondary to personal needs, with individuals tailoring tangible heritage to their living and evolving requirements for home or workplace. Functional and personal aesthetic needs take precedence over heritage values and a sense of place. Often innocent ignorance of planning systems results in failure to comply with due process of planning regulations. Resources and time, as well as tension and hearsay of unfortunate experience with local bureaucracy, can lead to distrust of the planning and regulatory systems for the management and protection of heritage buildings. People see themselves as disenfranchised from the local heritage debate; and report observing an imbalance in the interpretation of the legislative and regulatory framework. They regard local planning authorities as failing to reflect the core principles of regulation: proportionality, accountability, consistency, transparency and of targeting. This research answers questions about why people do not comply with the planning regulatory framework for heritage buildings. It concludes that those owning or working within heritage buildings must be treated as full partners in the heritage debate, or substantial unknown archaeological fabric will continue to be lost without record.

Abstract: This study presents the first approach to the use of the pocket-size molecular sensor SCiO in the field of cultural heritage. The portable, non-invasive, and compact instrument was developed in 2014 as a Startup project of Consumer Physics (Tel Aviv, Israel), bringing Near-Infrared Spectroscopy NIRS to consumers mostly interested in the agricultural field. The main purpose of the project was to explore possible areas of application in cultural heritage in which SCiO could be useful, evaluating the performance and suitability of the instrument, same as future lines of work and improvements. The methodology and results obtained, including the analysis of the spectra, can be a point of reference for future studies using SCiO or similar devices that use NIR. The materials tested in this study were paintings materials; pigment, binder, and varnish reference samples, a canvas painting reproduction, and five paintings of the Italian artist Lino Piccoli (1926-2010), selected as case studies to make possible the exploration of the painter’s palette.

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.

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.

Among the most representative materials of XX Century architectural heritage, this dissertation focuses on the cement-based ones, investigating some different fields where they were exploited. Primarily, concerning the surface preservation of cement-based materials used with aesthetic intent, new self-cleaning treatments based on titania nanoparticles embedded in inorganic matrices were tested. In order to consider the role of porosity, the treatments were applied to different kinds of materials (cement-based mortar, marble and concrete) and several analyses were conducted to investigate the morphology of the coatings, their photocatalytic effectiveness, their durability and the interaction between the coating and the substrate material. The outcomes showed that several parameters influence the treatment’s performances, in particular, the presence and nature of the matrix, the concentration and dispersion of nanoparticles and, in some cases, the amount of substrate material which interacts with the coatings. Secondly, this dissertation deals with the historic “Terranova” render, a colored dry-mix mortar largely widespread in Europe in the first half of XX Century, whose formulation is still basically unknown. Some original samples of supposedly Terranova renders were subjected to several characterization analyses and the results were compared to those of the original “Terranova” render of the Engineering Faculty in Bologna. Despite the recurrence of some features, defining a common formulation seemed to be challenging. Finally, the repair and conservation of structural reinforced concrete in heritage buildings were investigated, adopting the former “Casa del Fascio” in Predappio (FC, Italy) as case study. Three different materials and solutions were tested on a slab of the building, making its repair only from the intrados. Then several analyses were conducted both on site and in laboratory. Aside from the specific features characterizing every product, the results highlighted that the application method played a fundamental role in the effectiveness of the retrofit strategies.

Recent observations have shown that many sandstone buildings, including important components of the UK's cultural heritage, are becoming covered with green algal growths. This is likely to result from recent changes in air quality and the impacts of a changing climate. The northern regions of the UK in particular have an abundance of sandstone heritage and, given the likelihood of warmer, wetter winters here, algal growth on vulnerable monuments is likely to become a primary conservation concern over the next 50 years. Observations of sandstone monuments in the northern regions of the UK, in particular in Belfast (Northern Ireland), Sheffield and Edinburgh have highlighted that algal greening is notably patchy. This is likely due to the array of factors which affect the bioreceptivity of host substrates such as sandstone. The bioreceptivity of a substrate (its ability to become colonised by microbes such as green algae) is dependent on inherent, external and architectural factors. The role of these factors and the interrelationships between them requires further study. This thesis aims to investigate the inherent, external and architectural factors which encourage colonisation of sandstone by green algae through an integrated programme of laboratory and field experimentation. The primary objectives of this study are: to develop improved laboratory experimental methods to control and monitor algal growth, to investigate the role of external, inherent and architectural factors and to explore the fundamental role of moisture in the development of algal greening. In order to address these objectives, laboratory and field experiments have been linked within an integrated overall methodology. Short-term laboratory experiments have investigated the bioreceptivity of four British sandstones (Peak Moor, Dungannon, St Bees and 'baluster stone') to single and mixed green algal treatment with Stichococcus bacillaris, Chlorella vulgaris and Desmococcus olivaceus, under controlled conditions. Two field experiments have also been conducted. The first exposed unweathered blocks of Dungannon sandstone in the wet environment of Derrygonnelly, Northern Ireland for 30 months. The second exposed reclaimed sandstone balusters in a shaded and exposed site in central Oxford for 12 months. The laboratory and field experiments presented utlilise a range of simple and accessible methods to monitor biofilm development (for example novel methods to map biomass) and changes in substrate condition (such as monitoring surface moisture movements with weight change and hand-held moisture meters, and using light microscopy to help visualise the impact of green algal biofilms). The results presented in this thesis confirm that moisture plays a fundamental role in the development of green algal biofilms. In laboratory experiments, colonisation often occurred within a consistent moisture zone and preferential greening in field experiments was observed in areas of frequent moisture movement. External factors have been shown to have a strong influence, in laboratory experiments where marine salts were applied, these were found to delay colonisation by around seven days. Furthermore, salts resulted in inhomogeneous patterns of colonisation, similar to those observed in scoping studies conducted in Sheffield. Laboratory experiments have also demonstrated that inherent substrate factors such as high porosity and presence of certain minerals (such as clay laminations in Dungannon) can increase the primary bioreceptivity of sandstone surfaces. Field experiments have demonstrated that architectural factors such as aspect and geometry can increase the bioreceptivity of exposed samples. In particular, preferential greening was observed on the dynamically wetted south west facing blocks in Derrygonnelly and on exposed compared with shaded balusters in Oxford. Greening was also concentrated in areas of rainwater flows and stores. Investigation of the role of external, inherent and architectural factors in the development of algal greening as provided by this project, supplies useful information for those managing our sandstone cultural heritage. This will enable more informed decisions to be made over appropriate management and conservation strategies for the future.

L’alteració dels materials constructius es deguda principalment a les condicions climàtiques i als contaminants ambientals. Dins dels diversos processos de degradació que poden afectar la pedra, emprada tant com material estructural com decoratiu, aquest treball es centra en la desintegració superficial. El tractament de conservació utilitzat per a la recuperació de la cohesió superficial de la pedra es la consolidació. L’objectiu d’aquest treball es sintetitzar i avaluar l’aplicació de consolidants efectius i compatibles amb la pedra calcària. La compatibilitat és actualment un concepte de gran importància en els tractaments de conservació, per tal de mantenir la màxima estabilitat i durabilitat del tractament i per evitar que es modifiquen les propietats hídriques del suport y la creació d’estrès i envelliment diferencial. Dos tipus de consolidants compatibles han estat proposats. El primer es basa en suspensions de nanopartícules de calç, en base alcohòlica i en base aquosa. La síntesi ha estat realitzada en microemulsions micel·lars inverses, millorant finalment la penetració del producte en la seva aplicació. La síntesi del segon consolidant consisteix en la formació de hidroxiapatatita mitjançant el procés de sol-gel. La investigació de nous precursors de reacció i la optimització del procés han portat a obtenir un producte amb resultats molt favorables en la seva aplicació. El tractament amb els consolidants sintetitzats ha estat avaluat en comparació amb altres dos consolidants comercials, sobre pedres envellides artificialment i sobre morters de calç pintats. En la valoració dels assajos realitzats, les propietats petrofísiques, mecàniques i estètiques de la pedra han estat considerades.
La alteración de los materiales constructivos se debe principalmente a las condiciones climáticas y a los contaminantes ambientales a los que se enfrenta. De entre las diversas formas de degradación que puede sufrir la piedra, empleada como material estructural o decorativo, este trabajo se centra en la desintegración superficial. El tratamiento de conservación recomendado para la recuperación de la cohesión superficial de la piedra es la consolidación. El objetivo de este trabajo es sintetizar y evaluar la aplicación de consolidantes efectivos y compatibles con la piedra calcárea. La compatibilidad es actualmente un concepto de gran importancia en los tratamientos de conservación. Con ello se pretende mantener la máxima estabilidad y durabilidad del tratamiento y evitar que se modifiquen las propiedades hídricas del soporte y la creación de stress y el envejecimiento diferencial. Se han propuesto dos tipos de consolidantes compatibles. El primero de ellos basado en suspensiones de nanopartículas de cal, en base alcohólica y en base acuosa. La síntesis se ha realizado en microemulsiones de micelas inversas, mejorando la penetración del producto en la aplicación final. La síntesis del segundo consolidante consiste en la formación de hidroxiapatita mediante el proceso de sol-gel. La investigación de nuevos precursores de reacción y la optimización del proceso han llevado a obtener un producto con resultados prometedores en su aplicación. El tratamiento con los consolidantes sintetizados ha sido evaluado en comparativa con otros dos consolidantes comerciales, sobre piedras envejecidas artificialmente y sobre morteros de cal pintados. En la valoración de los ensayos realizados se ha tenido en cuenta las propiedades petrofísicas, mecánicas y estéticas de la piedra.
The key factors in building material degradation are climatic conditions and atmospheric pollutants. Although there are the many processes which can alter stone in either a structural or decorative context, superficial disintegration is the process focused upon in this work. Consolidation is the recommended treatment for the recovery of the superficial cohesion of stone. The aim of this work is to synthetize and to evaluate the application of effective and compatible consolidants for limestone. Nowadays, conservation cures place significant importance upon compatibility in order to achieve the maximum stability and durability of the treatment, to avoid on one hand the modification of the stone’s hydric properties, and on the other, the creation of differential stress and ageing. Two types of compatible consolidants are proposed. The first consolidant is based in lime nanoparticles, in both alcohol and water suspensions. The synthesis has been conducted in inverse micelles microemulsions. The penetration depth in the final application of the product has been improved. The second consolidant synthesis consists in the formation of hydroxyapatite by sol-gel process. New reaction precursor research and the optimization of the process have led to the achievement of a product with promising results in its application. The assessment of the consolidation treatment performed with the synthetized product has been compared to commercial consolidants on artificially aged stones and on painted lime mortars. These test evaluations has been developed considering the petrophisic, mechanical, and esthetic properties of the stone.

The importance of scientific analyses on artworks has become more and more crucial in the articulate processes of conservation and restoration. Moreover, the complexity of artistic materials, composed by organic and inorganic substances mixed together and often aged, requires extremely sensitive but user-friendly analytical tools. For this reason, the request of effective non-invasive diagnostic techniques is steadily increasing. In particular, a challenging task is represented by organic compounds, which can be found in the artistic field with a wide range of applications: they are binders used to spread pigments in paintings, varnishes, coatings and adhesives applied by the artist himself or during the restoration works, and colouring substances. Among the latter two different typologies can be individuated, namely natural dyes, used from the antiquity to dye textiles and in paintings in form of lakes, and a quite recent family of pigments, the synthetic organic ones. The detection of such materials can be hardly achieved by the non-invasive and in-situ appliable analytical techniques commonly employed in the field of conservation science. Briefly, X-ray fluorescence cannot provide useful information as it detects only elements with medium to high atomic number, while infrared and Raman spectroscopies are affected by the problem of fluorescence emission and of the matrix interference respectively. This Ph.D. thesis work was intended to develop innovative strategies based on molecular spectroscopies, pursuing the objective of non-invasively identifying the most common organic materials which can be found in museum objects, mainly focusing the attention on paintings (binders and synthetic organic pigments) and ancient textiles (natural dyes). In particular, spectrofluorimetry was proposed for the identification of synthetic organic pigments, a quite recent category of colourants since they were introduced by Perkin in the second half of the 19th century. The fluorescence emission upon visible excitation exhibited by several organic pigments used in contemporary artworks was successfully demonstrated and an analytical approach combining visible-induced spectrofluorimetry and visible-reflectance spectroscopy with a multivariate processing of data was established. The effectiveness of the method was finally confirmed by its application to three contemporary paintings. In addition, the possibility of exploiting fluorescence emission induced by UV radiation was considered, as well as the prospect of investigating such materials by ultraviolet fluorescence (UVF), visible and infrared luminescence (VIVF and VIL) images. The use of near-infrared (NIR) spectroscopy was proposed for the detection of organic binders and to understand the complex stratigraphy in paintings. This spectral region, in particular in the range 6500-4000 cm-1, is dominated by combination and overtone bands due to functional groups typical of the lipidic and proteinaceous materials used as binding media, therefore it can be exploited for identification purposes. Moreover, it was demonstrated that the greater penetration depth of the NIR radiation in comparison with the mid-infrared (MIR) one allows the investigation of the preparatory layers possibly applied by the artist on the painting support. In this respect, an exhaustive study was carried out at first on a consistent number of reference mock-up samples, prepared on the basis of ancient recipes, and then on eight paintings, dating from the end of the 15th century to the end of the 18th century and exemplifying different artistic techniques on different supports. Finally, the main part of the work was dedicated to surface-enhanced Raman spectroscopy (SERS) for the identification of natural dyes in textiles. This technique, which exploits the strong intensification by several orders of magnitude of the Raman scattering of organic molecules in the proximity of metal nanoparticles and nanostructured surfaces, is a well-established method for the detection of dyes, but generally requires the extraction of the target analyte from a sample. Many experiments were performed therefore performed to develop SERS-sensors suitable for performing measurements directly from dyed fibres in dry-state condition, i.e without requiring extraction protocols or the placement of a wet substrate in contact with the artefact. In this respect, a general, easy-to-apply protocol involving the deposition of colloidal nanoparticles on glass supports was developed. The importance of hot spots, areas of strong SERS intensification of the Raman signal formed between close nanoparticles or on anisotropic structures rich in tips, leads to experiment different aggregation procedures and nanoparticle shapes, ranging from nanospheres to nanostars and nanorods. The final aim was to create reproducible and homogeneous sensors, able to provide a high SERS enhancement when just put in contact in dry-state conditions with the artistic object under investigation. In this respect silver was demonstrated to be the best metal in comparison with gold and the most effective substrates, allowing the identification of four historical dyes from dyed wool yarn, were those obtained from silver nanostars. Finally, also some related issues are faced, such as the release of metal on the sample and the cleaning of the substrate surface exploiting the photochemical properties of titanium dioxide.

For Cultural Heritage materials is important to guarantee a correct conservation and vision of the artefacts, enhancing the observer experience assuring the best visual and conceptual appearance of artefacts. Several factors affect the visual appearance of artistic materials. However, available measurement methodologies for the material characterisation are not able to accurately predict the visual appearance of materials usually used in cultural heritage. Goals of the thesis research was to identify the visual attributes that mainly affect the appearance of artworks, investigate the correlation between measured data and visual human response and individuate if there are measured conditions that allow a better correlation. Finally, provide useful suggestion to aid in planning and selecting adequate conservative intervention, such as restoration work. In order to reach these purposes, different samples representative of materials used in artistic artefacts were selected and realised and two different visual testes were set up and carried out investigating the influence of lighting and viewing conditions on the human visual response of selected visual attributes: glossiness, colour (saturation), brightness and sparkling. The first visual test takes into account how the human visual responses on glossiness and saturation are affected by the lighting and viewing conditions using coloured samples with different levels of gloss obtained brushed on them different mixture of natural varnishes. While, in the second visual test were identified the elements that mainly affect the human perception of sparkling and brightness in monochromatic samples with mica particles, a mineral easily found in ornamental stones. At the end of each visual test, all responses were statistical analysed and, then, the results were compared with the corresponding objective measured data. In this way, it was possible to define what measurement conditions allow to have a better correlation with the subjective assessment.

In this doctoral dissertation, photochemical and, in some cases, thermal aging (natural and accelerated) of materials from cultural heritage (paper, parchment, linseed oil paints, pigments and dyes) are studied with a number of both destructive and non-destructive experimental techniques such as Electron Paramagnetic Resonance (EPR) , Nuclear Magnetic Resonance-MObile Universal Surface Explorer (NMR-MOUSE) , High Performance Liquid Chromatography-Photo Diode Array (HPLC-PDA) , Liquid Chromatography-Mass Spectrometry (LC-MS) , Fiber Optics Reflectance Spectroscopy (FORS)3,1, Attenuated Total Reflectance-Infrared spectroscopy (ATR-IR) , micro-fading-meter3 and Xenotest exposure device3. My research activity was carried out in collaboration with the Chemical Sciences Department of the University of Padua, the Netherlands Institute for Cultural Heritage (Amsterdam) and the Image Permanence Institute (Rochester Institute of Technology, NY) and thanks to the accessibility to the Van Gogh Museum collection. In chapters one and two, an introduction to the history of colorants and to colorimetry and a description of the degradation reactions induced by light and by common gaseous pollutants are presented. In chapters three, four and five, the results of my research activity are analyzed. In particular, in chapter three of my doctoral dissertation, Writing Materials, the dependence of chemical-physical properties of paper and parchment on aging is investigated with an NMR device called MOUSE. NMR-MOUSE is an instrument of great potential in the field of conservation science because it enables the measurement of nuclear relaxation times of various materials in situ and without sampling. Nuclear relaxation times are directly related to the chemical-physical nature of materials and were proved to be markers of the state of conservation of paper. As for parchment, nuclear relaxation times enabled to distinguish between samples from the XX century and XVIII century. For both materials, different environments for water (bound or free molecules) could be recognized. In chapter four, Pigments and Dyes, a number of EPR spectra of known and unknown pigments is provided. In addition, the effect of different pigments or dyes on polymerization of linseed oil paints is revealed with NMR-MOUSE. EPR spectroscopy was demonstrated to be effective in discriminating different pigments or classes of pigments with micro-invasive sampling. Relaxation times of linseed oil paints were demonstrated to be sensitive to the presence of pigments and an interpretation of the results in terms of different rates or degree of polymerization was given. In chapter five, Dyes in Aqueous Solution and on Paper: Discoloration and Fading of Crystal Violet, which represents the main body of my doctoral research activity, an extensive analysis (HPLC-PDA, LC-MS, FORS, EPR, micro-fading assessments, Xenotest exposure device) of the photo-fading and thermal aging of an early synthetic dye (Crystal Violet) in aqueous solution and on paper is presented. The interest on the subject stems from the discoloration occurred on a group of Van Gogh drawings and letters all produced in 1888 in Arles and all made with a type of purple ink which was demonstrated to contain crystal violet and other structurally related derivatives (triarylmethane dyes). In particular, a seemingly brown drawing belonging to this group and entitled Montmajour (Arles, 1888. Van Gogh Museum) shows purple shades on the edges where the ink has been protected from light under the frame. Another example, although not belonging to the Arles group, is a menu (Paris, 1886. Van Gogh Museum) drawn and written by Van Gogh with purple ink, as can be inferred from a reproduction made in 1958. Nevertheless, in a picture of the menu taken in 2001 it can be seen that the writings and part of the drawings had disappeared entirely. Interestingly, although FORS analysis revealed the presence of ink containing triarylmethane dyes, in this case no brown discoloration was visible. With the aim of shedding light on aging mechanisms and discoloration of inks containing crystal violet on paper, accelerated aging experiments were conducted for pure crystal violet both in aqueous solution and on paper. Various experimental parameters were taken into consideration: the spectral range of the light source (UV or Vis), the paper substrate (pure cellulose paper, lignin paper, printing paper), temperature and the presence or absence of oxygen during irradiation. Moreover, a purple ink containing methyl violet (a mixture of crystal violet and some of its demethylated derivatives) was reconstructed (by Judith Geerts, student of the University of Amsterdam, according to a recipe by Sigmund Lehner, 1909) and its thermal (100 °C) and photo fading (UV light and natural sun light) was studied on different paper substrates (cellulose paper, lignin paper and protein-sized paper). The effect of various ink additives (gum arabic, sucrose and oxalic acid), of Fe(III) (as an example of photo-catalyst often present as an impurity in paper) and of common gaseous pollutants such as NO2 and O3, on the color of dyed (or written) samples of paper was also taken into consideration. A group of ten historical samples of methyl violet from the ICN dye collection was also analyzed with HPLC-PDA, with the aim of comparing actual dye samples with both the model samples described in this doctoral dissertation and with the purple ink of the ‘Montmajour’ drawing (Arles, 1888. Van Gogh Museum). Successively, some dyes and pigments (cochineal ink, indigo blue ink, indigo carmine, copper logwood synthesized from CuSO4 or Cu(AcO)2 and chromium logwood) used in the XIX century as alternative ingredients for purple inks were deposited on paper and artificially aged with UV light or heat. A colorimetric analysis of the samples was conducted before and after aging. Finally, a group of letters from the XIX century (Birgit Reissland, private collection) was analyzed with FORS and the presence of dyes closely related to crystal violet was detected. The analysis presented in chapter five of this doctoral dissertation has thus demonstrated that the synthetic dye methyl violet was widely used after its introduction to the market in 1866. Moreover, the poor lightfastness of crystal violet was explained to be due to demethylation and oxidation reactions. A series of degradation products was identified with HPLC-PDA and LC-MS both for crystal violet in aqueous solution and on paper after exposure to UV in the presence of oxygen. HPLC-PDA analysis of a sample of purple ink from the ‘Montmajour’ drawing (Arles, 1888. Van Gogh Museum) was in good agreement with the results of these model samples. The complete fading observed on the Menu was reproduced and explained as due to light exposure (UV or visible). According to my experimental results, the first stage of the degradation mechanism consists of a series of demethylation reactions eventually leading to pararosaniline, a red dye corresponding to fully demethylated crystal violet. Afterwards, oxidation at the central carbon atom forms colorless (or slightly yellow) ketones responsible both for the fading of crystal violet and for a sensitization effect on dye degradation. The presence of oxidized derivatives of Crystal Violet has also been demonstrated. As for the position of the oxygen attack, it has been hypothesized the formation of N-oxides of crystal violet or of its demethylated derivatives. Heat (50 °C, 40% relative humidity) was shown to play a minor role in the fading of crystal violet on paper whereas visible light alone was enough for the dye to fade visibly. Interestingly enough, considering the fact that anoxic protection is in use, crystal violet did fade on paper following the exposure to UV light in the absence of oxygen as well. The substrate (cellulose paper, lignin paper or printing paper), although it was not responsible for the nature of (colored) degradation products, played a role in determining the relative amounts products formed and the final color of the dye layer. Interestingly, both artificial aging (UV light) and natural aging (sun light) of samples of paper dyed with an ink containing methyl violet and other additives led to different colors than in the presence of pure crystal violet. In particular, the colors obtained were brownish-grey and bluish-grey, in the presence or in the absence of Fe(III) respectively. Moreover, the addition of Fe(III) or of ink additives (such as sucrose and oxalic) alone to paper, caused the formation of yellow or brown discoloration after exposure to sunlight. ATR-IR analysis of the yellow areas revealed the formation of carbonyl groups from cellulose and Fe(III). On the basis of the results of the aging tests of the reconstructed ink, an hypothesis for the brown discoloration of the Montmajour drawing is provided. Exposure to such a pollutant as NO2 of purple ink containing methyl violet applied on different paper substrates (cellulose paper, lignin paper and protein-sized paper) produced a strong darkening of ink which turned bluish-black or black on all substrates. On cellulose paper, pure crystal violet faded to light blue. LC-MS analysis of the dyes extracted from this sample revealed the formation of at least one nitrosamine, due to the attack of the gas at one of the nitrogen atoms of the dye molecule. Exposure to O3 did not lead to a significant color change of Crystal Violet on paper. Accelerated aging experiments on pigments and dyes used as alternative ingredients for purple inks have brought about significant discoloration effects. Among others, copper logwood produced from copper sulphate and logwood extract showed a color shift from blue to reddish-brown after aging (in particular after thermal aging) and indigo carmine has faded entirely after exposure to UV light. These experimental results therefore demonstrate the importance of reliable reconstructions of museum objects where the co presence of various components (e.g. additives, impurities, different paper substrate) can lead to peculiar interactions or color effects. To this regard, cooperation between natural scientists, art historians, conservators and restorers should be pursued both in order to get a complete characterization of a piece of artwork and so as not to misinterpret partial data coming from a single research field.
La presente tesi di dottorato riguarda lo studio dei fenomeni di invecchiamento naturale e accelerato di tipo foto-chimico (e in alcuni casi termico), di materiali di interesse artistico (carta, pergamena, colori a olio, pigmenti e coloranti) attraverso numerose tecniche sperimentali, sia distruttive che non, quali Electron Paramagnetic Resonance (EPR) , Nuclear Magnetic Resonance-MObile Universal Surface Explorer (NMR-MOUSE) , High Performance Liquid Chromatography-Photo Diode Array (HPLC-PDA) , Liquid Chromatography-Mass Spectrometry (LC-MS) , Fiber Optics Reflectance Spectroscopy (FORS)3,1, Attenuated Total Reflectance-Infrared spectroscopy (ATR-IR) , micro-fading-meter3 e camera per test di invecchiamento solare accelerato Xenotest3. La mia attività di ricerca è stata svolta in collaborazione con il Dipartimento di Scienze Chimiche dell’Università degli Studi di Padova, il Netherlands Institute for Cultural Heritage di Amsterdam (ICN) e l’Image Permanence Institute (Rochester Institute of Technology, New York) e grazie all’accessibilità alla collezione del Museo Van Gogh di Amsterdam. Il primo e il secondo capitolo forniscono una introduzione alla storia dei coloranti e alla colorimetria e una descrizione delle reazioni di degrado indotte dalla luce e da comuni gas inquinanti. Nei capitoli numero tre, quattro e cinque, vengono invece presentati i risultati della mia attività di ricerca. In particolare, nel terzo capitolo della mia tesi di dottorato, intitolato ‘Materiali Scrittori’, viene analizzata la dipendenza di proprietà chimico-fisiche della carta e della pergamena dall’invecchiamento, attraverso l’uso di una sonda NMR nota come MOUSE. Lo strumento NMR-MOUSE ha dimostrato di avere grandi potenzialità nel campo della scienza della conservazione in quanto permette di misurare i tempi di rilassamento nucleari di svariati materiali in situ e senza alcun campionamento. I tempi di rilassamento nucleari dipendono dalla natura chimico-fisica dei materiali ed è stato dimostrato come costituiscano anche degli indicatori dello stato di conservazione della carta. Per quanto riguarda la pergamena, i tempi di rilassamento nucleari hanno permesso di discriminare fra campioni del XX secolo e del XVIII secolo. Inoltre, per entrambi i materiali, lo strumento NMR-MOUSE ha permesso di individuare due intorni chimico-fisici per le molecole d’acqua costituenti i materiali stessi. Si tratta, nel primo caso, di molecole d’acqua libere (acqua liquida) e, nel secondo, di molecole legate chimicamente al substrato cellulosico o proteico. Nel quarto capitolo, intitolato ‘Pigmenti e Coloranti’, sono riportati svariati spettri EPR di pigmenti e coloranti, la cui natura chimica era nota solo in alcuni casi. Inoltre, con lo strumento NMR-MOUSE è stato osservato l’effetto della presenza di diversi pigmenti o coloranti sulla polimerizzazione dell’olio di lino. La spettroscopia EPR si è dimostrata efficace nel discriminare fra diversi pigmenti o classi di pigmenti anche con campionamenti micro-invasivi. Inoltre, i tempi di rilassamento nucleari di colori a base di olio di lino si sono dimostrati essere dipendenti dalla presenza dei pigmenti e i risultati sono stati interpretati in termini di diverse velocità o gradi di polimerizzazione. Il quinto capitolo, intitolato ‘Dyes in Aqueous Solution and on Paper: Discoloration and Fading of Crystal Violet’, rappresenta il corpo principale di questa tesi di dottorato e consiste in un’estesa analisi (HPLC-PDA, LC-MS, FORS, EPR, valutazioni di micro-fading, camera per test di invecchiamento solare accelerato Xenotest) dei processi di invecchiamento foto-indotto e termico di uno dei primi coloranti organici sintetici, il crystal violet, in soluzione acquosa e su carta. L’interesse per questo argomento ha origine dall’osservazione dei fenomeni di alterazione cromatica che interessano un gruppo di disegni e lettere di Van Gogh, tutti prodotti ad Arles nel 1888 con un inchiostro viola che è stato dimostrato contenere crystal violet o altri coloranti strutturalmente correlati (coloranti del triafenilmetano). In particolare, il ‘Montmajour’ (Arles, 1888. Van Gogh Museum), ¬un disegno apparentemente di colore marrone e appartenente al detto gruppo, mostra delle tracce di inchiostro viola sui bordi del foglio, dove l’inchiostro è stato protetto dalla luce sotto la cornice. Un altro esempio, anche se non appartenente al gruppo di Arles, è costituito da un menù (Parigi, 1886. Museo Van Gogh) scritto e disegnato da Van Gogh con un inchiostro viola, come è stato possibile stabilire da una riproduzione dell’opera risalente al 1958. Tuttavia, in una foto del 2001 si può constatate come il testo e parte del disegno fossero completamente sbiaditi. E’ interessante notare come in questo caso, benché da un’analisi con spettroscopia FORS siano state rilevate tracce di coloranti del trifenilmetano, non si è osservato l’imbrunimento dell’inchiostro tipico del ‘Montmajour’. Con l’obiettivo di far luce sui meccanismi di invecchiamento e di alterazione cromatica degli inchiostri contenenti crystal violet su carta, sono stati condotti degli esperimenti di invecchiamento accelerato di crystal violet puro, sia in soluzione acquosa che su carta. Numerosi parametri sperimentali sono stati presi in considerazione: l’intervallo spettrale della sorgente di luce (UV o visibile), il substrato cartaceo (di pura cellulosa, contenente lignina o da fotocopie), la temperatura e la presenza (o assenza) di ossigeno durante l’irraggiamento. Inoltre, è stato riprodotto (da parte di Judith Geerts, studentessa dell’Università di Amsterdam) un inchiostro viola a base di methyl violet (a base cioè di una miscela di crystal violet e alcuni dei suoi prodotti di demetilazione) secondo una ricetta di Sigmund Lehner (1909) e il suo degrado foto-indotto (luce UV e luce solare naturale) e termico (100 °C) è stato studiato su diversi substrati cartacei (carta di cellulosa, carta di lignina e carta collata con proteine). Inoltre, sono stati presi in considerazione anche gli effetti, sul colore di campioni di carta tinta, di alcuni additivi utilizzati negli inchiostri (gomma arabica, saccarosio e acido ossalico), del Fe(III) (come esempio di foto-catalizzatore spesso presente nella carta come impurezza) e di comuni gas inquinanti, quali NO2 e O3. E’ stato analizzato via HPLC-PDA anche un gruppo di dieci campioni storici di methyl violet provenienti dalla collezione dell’ICN al fine di poter confrontare campioni reali di coloranti sia con i campioni modello descritti nella presente tesi di dottorato che con un campione dell’inchiostro viola del disegno ‘Montmajour’ (Arles, 1888. Museo Van Gogh). Successivamente, sono stati depositati su carta e invecchiati artificialmente (con luce UV o per trattamento termico) alcuni pigmenti e coloranti (inchiostro a base di cocciniglia o indaco, carminio d’indaco, colorante a base di estratto di campeggio e cromo e colorante a base di estratto di campeggio e rame sintetizzato a partire da CuSO4 o Cu(AcO)2) utilizzati nel XIX secolo come ingredienti per la produzione di inchiostri viola in alternativa al crystal violet. Infine, è stato analizzato con la spettroscopia FORS un gruppo di lettere del XIX secolo (Birgit Reissland, collezione privata) ed è stata rivelata la presenza di coloranti strettamente correlati al crystal violet. L’analisi presentata nel quinto capitolo della presente tesi di dottorato ha quindi dimostrato che l’uso del colorante sintetico methyl violet era molto diffuso dopo la sua introduzione nel mercato avvenuta nel 1866. Inoltre, la scarsa resistenza alla luce del crystal violet è stata spiegata come dovuta a reazioni di demetilazione e ossidazione. Una serie di prodotti di degrado è stata identificata con HPLC-PDA e LC-MS per il crystal violet esposto a luce UV in presenza di ossigeno, sia in soluzione acquosa che su carta. L’analisi HPLC-PDA di un campione di inchiostro viola prelevato dal disegno ‘Montmajour’ (Arles, 1888. Museo Van Gogh) si è dimostrata in accordo con i risultati dei campioni modello appena descritti. Lo sbiadimento completo osservato nel menù è stato riprodotto e spiegato come il risultato dell’esposizione alla luce (UV o visibile). Sulla base dei miei risultati sperimentali, il primo stadio del meccanismo di degrado consiste di una serie di reazioni di demetilazione che porta come ultimo stadio alla pararosaniline, un colorante rosso corrispondente alla completa demetilazione del crystal violet. Successivamente, l’ossidazione in corrispondenza dell’atomo di carbonio centrale forma chetoni incolore (o debolmente gialli), responsabili sia dello sbiadimento del crystal violet che di un effetto di sensibilizzazione del colorante rispetto al degrado foto-indotto. E’ anche stata rivelata la presenza di derivati ossidati del crystal violet. Per quanto riguarda la posizione dell’attacco da parte dell’ossigeno, è stata ipotizzata la formazione di N-ossidi del crystal volet o dei suoi prodotti di demetilazione. Si è dimostrato anche come il calore (50 °C, 40% umidità relativa) abbia un ruolo secondario nel degrado del crystal violet su carta mentre l’esposizione a sola luce visibile è stata sufficiente a sbiadire completamente il colorante. Particolarmente interessante, considerato che la protezione in ambiente anossico è una delle tecniche di conservazione adottate nei musei, è il fatto che il crystal violet ha mostrato evidenti segni di sbiadimento anche a seguito di esperimenti di esposizione a luce UV in assenza di ossigeno. Il substrato cartaceo (carta di cellulosa, di lignina o da fotocopie), benché non responsabile per la natura dei prodotti di degrado (colorati) rivelati, ha determinato le quantità relative dei prodotti formati e il colore assunto dallo strato di colorante. E’ interessante notare come sia l’invecchiamento artificiale (luce UV) che quello naturale (alla luce del sole) di campioni di carta tinti con l’inchiostro contenente methyl violet e altri additivi, abbiano dato origine a colorazioni diverse da quella ottenuta in presenza di crystal violet puro. In particolare, i colori ottenuti sono un grigio-bruno o un grigio-blu, rispettivamente in presenza e assenza di Fe(III). Inoltre, la sola aggiunta di Fe(III) o additivi (tipo saccarosio o acido ossalico) alla carta ha causato la formazione di macchie gialle o brune dopo l’esposizione alla luce solare. L’analisi ATR-IR delle aree ingiallite ha rivelato la formazione di gruppi carbonilici a partire da cellulosa e Fe(III). Sulla base dei risultati dei test di invecchiamento dell’inchiostro ricostruito, è stato possibile formulare un’ipotesi per spiegare le cause del colore bruno apparso sul ‘Montmajour’. L’esposizione ad un inquinante quale il biossido di azoto (NO2) dell’inchiostro a base di methyl violet applicato su diversi substrati cartacei (di cellulosa, di lignina o collati con proteine) ha prodotto un forte scurimento dell’inchiostro, che è diventato nero-blu o nero, in tutti i substrati cartacei. Per quanto riguarda invece il crystal violet puro, si è ottenuto uno sbiadimento ad azzurro chiaro su carta di pura cellulosa. L’analisi LC-MS di quest’ultimo campione ha rivelato la presenza di almeno una nitrosoammina dovuta all’attacco del gas su uno degli atomi di azoto della molecola di colorante. L’esposizione ad ozono (O3) non ha invece prodotto una variazione significativa del colore del crystal violet puro su carta. Gli esperimenti di invecchiamento accelerato sui pigmenti e i coloranti utilizzati come ingredienti alternativi per la preparazione di inchiostri viola, hanno condotto a importanti alterazioni cromatiche. Fra gli altri, il colorante a base di estratto di campeggio e rame prodotto da solfato di rame ha mostrato una variazione di colore dal blu al bruno rossiccio a seguito dell’invecchiamento (termico in particolare) e il carminio d’indaco è sbiadito interamente dopo esposizione alla luce UV. Questi risultati sperimentali, quindi, hanno dimostrato l’importanza di avere a disposizione affidabili ricostruzioni degli oggetti museali, dove la compresenza di varie componenti (ad esempio additivi, impurezze, diversi substrati cartacei) può portare a particolari interazioni chimiche o influenzare il colore percepito. A questo proposito, sarebbe auspicabile la cooperazione fra scienziati, storici dell’arte, conservatori e restauratori, al fine di poter ottenere una caratterizzazione completa di un’opera d’arte e così da non malinterpretare i dati parziali provenienti da un singola campo di ricerca.

Devido à relevância das proteínas como componentes das pinturas de cavalete, o seu reconhecimento é de grande interesse para caracterizar a técnica artística e para fins de conservação e restauro. Infelizmente, a degradação dos materiais originais, a coexistência de diferentes proteínas e as matrizes complexas das pinturas, tornam esta tarefa particularmente difícil de ser conseguida. Neste trabalho selecionaram-se aglutinantes proteicos (colas) comummente utilizados nas pinturas de cavalete, testaram-se anticorpos para o reconhecimento das colas de coelho e desenvolveram-se ensaios em microamostras de provetes de camada de preparação para pintura de cavalete. As colas são constituídas maioritariamente por proteínas, e os resultados mostram a presença de proteínas distintas, consoante a origem da cola animal. Quatro dos dez anticorpos testados reconheceram a cola de pele de coelho e o anticorpo 3.14 permitiu um reconhecimento seletivo deste aglutinante nas provetes, abrindo a possibilidade de se poder vir a utilizar este anticorpo em amostras reais; Utilisation and characterisation of antibodies to identify proteic binders in easel paintings Abstract: Due to the relevance of proteins as components in easel paintings, its recognition is of great interest to characterize the artistic technique and for conservation and restauration purposes. Unfortunately, the degradation of materials, the coexistence of different proteins and the complex matrices in paintings make this a particularly difficult task to achieve. In this work we selected proteic binders (glues) commonly used in easel paintings, test antibodies for the recognition of rabbit fur glue and developed assays in microsamples of specimens of preparation layer to easel paintings. The glues are constituted mostly by proteins and the results show the presence of distinct proteins according to the animal from which the glue origins. Four of the ten antibodies tested recognized the rabbit fur glue, and the antibody 3.14 allowed a selective recognition of the binder in microsamples, allowing the possibility of being able to use this antibody in real samples.

Lors de leur stockage ou de leur exposition, les objets du patrimoine sont soumis à des processus physico-chimiques d’altération liés à leur environnement et en particulier à l’action de polluants primaires (e.g. dioxyde de soufre, oxydes d’azote), secondaires (ozone) ou de composés organiques volatils (COVs). Il a été démontré que ces gaz/vapeurs se comportent comme des agents d’hydrolyse et d’oxydation. L’acide acétique fait partie des COVs ayant un impact considérable et reconnu dans la conservation des objets du patrimoine en particulier des films photographiques. En vue de lutter contre ses effets délétères, ce projet de thèse s’est focalisé sur la conception de nouveaux matériaux poreux hybrides multifonctionnels appelés « Metal-Organic Frameworks » (MOFs) pour la capture sélective de l’acide acétique en présence d’humidité (40% humidité relative) et à température ambiante. Les remarquables propriétés d’adsorption (sensibilité, sélectivité et capacité) et la grande versatilité des MOFs (balance hydrophile/hydrophobe, taille/forme des pores,…) ont été utilisés pour préconcentrer de façon sélective l’acide acétique en milieu humide. Les matériaux les plus performants ont ensuite été préparés sous forme de nanoparticules pour l’élaboration de films minces de qualité optique afin d’en étudier les propriétés d’adsorption et de co-adsorption (acide acétique/eau) par ellipsométrie. L’incorporation de nanoparticules métalliques plasmoniques a ensuite été effectuée afin de concevoir un capteur colorimétrique. L’objectif final de ce travail est de concevoir un nouveau type d’adsorbant caractérisé par une capacité et une sélectivité d’adsorption élevée et dont on pourrait aisément déterminer le niveau de saturation en acide acétique afin d’anticiper son remplacement et ainsi assurer la préservation des objets stockés et exposés dans les musées
During their storage or their exhibition, the cultural heritage objects undergo physicochemical alteration processes related to their environment and in particular to the action of primary (e.g. sulfur dioxide, nitric oxides), secondary (ozone) pollutants or Volatile Organic Compounds (VOCs). It has been demonstrated that these gases/vapors are involved in hydrolysis and oxidation reactions. Among the most common VOCs encountered in museums, Acetic acid has a significant and recognized role in the deterioration of cultural heritage objects such as photographic films. In order to face this issue, this Ph.D. thesis focused on the design of new porous multifunctional hybrid materials denoted « Metal-Organic Frameworks » (MOFs) for the selective capture of acetic acid in the presence of moisture (40% relative humidity) and at room temperature. The remarkable adsorption properties (sensitivity, selectivity and capacity) and the great versatility of MOFs (hydrophicity/hydrophobicity balance, size/shape of pores,…) were used to preconcentrate selectively the acetic acid in humid conditions. The most performing materials were then prepared as nanoparticles and then used for the elaboration of high optical quality thin films in order to study the coadsorption (acetic acid/water) properties of MOFs by ellipsometry. The incorporation of plasmonic metal nanoparticles was then carried out in order to design a colorimetric sensor. The final objective is to devise a novel type of adsorbent that integrates a high VOC adsorption capacity and selectivity under humid conditions and an easy on-line monitoring of their saturation capacityin order to anticipate its replacement and therefore ensure the preservation of the stored and exhibited objects in museums

Restoration and conservation of the cultural and architectural heritage is a very complex topic in continuous developing. The issue raises interesting questions about the methodological approach to be followed and the objective from which it must be start for the definition of a correct restoration project. A regulatory-wide are creating and refining of a study procedures by means of the drafting of guidelines which intent is give a methodology and a sensitization at the problem at academic level, of public organs that control the conservation and the protection of the cultural heritage, and at the private technicians that work in this field. In Italy, a “normative effort” has been done by means of the production of technical documents that establish as evaluate the problem with more awareness. The aim is providing at the technicians the Guidelines about restoration of historical heritage. In the international field, from a general point of view, it is possible to refer to the ISCARSAH Recommendations, that give a preliminary approach to the topic. Currently, in this field different approaches are used: (1) a criteria based on the conservation, which puts attention to the form and to the materials of the building but less at the structural components, (2) a technical method that is more interested at the structure but, in many cases, involves over-dimensioned interventions than the real requirements, altering the original form and history of the building. The thesis is included in the current standards requirement and refers to the “Guidelines for evaluation and mitigation of seismic risk of cultural heritage” and the “Recommendations for the analysis, conservation and structural restoration of architectural heritage” ISCARSAH. Based on these documents, the study aims to providing an operative procedure able to balance the two approaches mentioned above. It has been identified a integrated and multi-disciplinary method for the study of cultural heritage, created in function of the currently codes and in respect of the fundamental standard of restoration and conservation. This method was made as generic as possible, without give particular information inherent specific restoration techniques, in such a way that is applicable at all the types of buildings with elevated historical-cultural valence. The methodology was validate through its application to two paradigmatic case studies, both located within the highly historical / sociological / architecture site, the Arsenal of Venice. The case studies are: (1) the “Sala Maggiore at the Sale d’Armi Nord” (Main Room of the North weapons rooms) and (2) the Armstrong Mitchell & Co. hydraulic crane. The choice of the two examples has been dictated by the objective requirements of the Soprintendenza B.A.P. di Venezia e Laguna (local office of the ministry of fine arts responsible for the conservation of the cultural and landscape heritage of Venice and its lagoon), to intervene in these two constructions of great historical and architectural content, which differ in geometry, materials, structural behaviour and intended use.
Il restauro e la conservazione di beni storici è oggi un tema molto discusso ed in fase di evoluzione sia in Italia che all’estero. Il tema pone degli interessanti interrogativi circa la metodologia di approccio da seguire e gli obiettivi dai quali si deve partire per la definizione di un corretto progetto di restauro. A livello normativo si stanno creando e affinando delle procedure di studio mediante la stesura di linee guida che hanno lo scopo di fornire una metodologia e una sensibilizzazione al problema a livello accademico, agli enti pubblici preposti alla conservazione e al restauro, e ai tecnici che lavorano in questo ambito. È infatti in atto un processo di “sforzo normativo” per colmare queste lacune mediante la produzione di documenti tecnici che si prefiggono di valutare il problema con maggior consapevolezza fornendo linee guida per il restauro di beni storici. Attualmente la materia in esame vede due differenti tipi di approccio: da una parte il restauro conservativo, in cui viene data importanza alla forma ed alla materia e meno alla componente strutturale, e dall’altra un criterio più tecnicistico, che pone più riguardo alla struttura ma che, in molti casi, comporta degli interventi più massicci che rischiano di falsare la forma e la storia originaria del bene. La tesi proposta si inserisce nel filone delle richieste normative, dei contenuti tecnici e dei documenti di riferimento quali le Linee Guida per i Beni Culturali e, a livello europeo, le Raccomandazioni ISCARSAH, ed intende fornire una procedura operativa per porsi nel giusto mezzo tra i due approcci sopra citati. Sono stati presi in considerazione vari documenti tecnici di riferimento ed è stato identificato un metodo integrato e mutidisciplinare per lo studio di beni storici, creato in funzione delle attuali normative e nel rispetto dei fondamentali criteri del restauro e della conservazione. Si è voluto rendere tale metodo il più generico possibile, senza fornire particolari informazioni inerenti specifiche tecniche di restauro, in modo tale che sia applicabile ad i vari tipi di beni storici. Per validare tale approccio, la metodologia identificata è stata applicata a due differenti casi studio, entrambi presenti all’interno del sito ad elevato valore storico/sociologico/architettonico quale l’Arsenale di Venezia, che si differenziano tra loro per materiali, destinazioni d’uso e comportamento strutturale: la Sala Maggiore delle Sale d’Armi Nord e la gru idraulica Armstrong, Mitchell & Co. La scelta dei due casi studio è stata dettata da concrete esigenze della Soprintendenza B.A.P di Venezia e Laguna di recuperare i due beni riportandoli alla loro configurazione originaria sia materica che strutturale.

La ricerca condotta ha riguardato lo studio di leganti, malte, materiali compositi e cementi a base di precursori alluminosilicatici attivati alcalinamente, valutandone l’idoneità in campo strutturale e nel particolare contesto della conservazione e ripristino del patrimonio culturale. E’ stata inoltre studiata l’interazione e l’uso sinergico degli AAMs con materiali lapidei naturali e artificiali. Sono stati prodotti leganti geopolimerici impiegando un caolino naturale di alto grado (73% caolinite e 27% quarzo) trattato termicamente a 800°C per due ore e silicato di sodio. Modificando il rapporto in peso acqua/solido tra 0.33 e 0.66 sono stati ottenuti leganti lavorabili senza ricorrere all’impiego di additivi fluidificanti. E’stata quindi valutata l’azione dell’acqua sullo sviluppo della reazione. I campioni hanno restituito elevati valori di resistenza a compressione e flessione (fino a 72 MPa e 6 MPa rispettivamente), tanto da ipotizzarne un impiego in applicazioni strutturali. E’ stato notato un aumento della porosità (dal 21% al 32%) e della dimensione media dei pori all’aumentare del contenuto di acqua. Analisi tramite spettroscopia infrarossa hanno permesso di correlare il grado di sviluppo del gel alluminosilicatico all’incremento del contenuto di acqua. I risultati ottenuti hanno mostrato che la diminuzione della resistenza meccanica nei campioni con crescente contenuto di acqua è da ascrivere ad un aumento della porosità piuttosto che ad una riduzione della conversione di metacaolino in geopolimero.Il legante geopolimerico con rapporto acqua/solido di 0.66 è stato utilizzato per la sintesi di malte, impiegando come aggregati due pietre ornamentali macinate, la Pietra Serena e la Pietra di Angera. La caratterizzazione fisico-meccanica ha restituito: i) valori di resistenza meccanica che rientrano nella classe M20; ii) valori di densità comparabili a quelle delle pietre ornamentali di riferimento; iii) valori di porosità variabili tra il 14 e 17%. La caratterizzazione chimica ha permesso di evidenziare, per la malta sintetizzata impiegando la Pietra Serena, come la frazione fine sembri contribuire alla reazione di geopolimerizzazione. Sono state effettuate inoltre misure colorimetriche per valutare la compatibilità estetica delle malte con le pietre ornamentali di riferimento.Il legante geopolimerico con rapporto acqua/solido di 0.46 è stato utilizzato per valutarne l’interazione all’interfaccia con materiali lapidei naturali (pietre ornamentali) e artificiali (laterizio, malta e calcestruzzo), attraverso analisi allo stereomicroscopio e al SEM. E’ stato evidenziato che la composizione dei materiali lapidei influenza le proprietà di adesione dei geopolimeri. Una matrice allumino-silicatica, come quella della Pietra Serena o del laterizio, ha mostrato maggiore affinità fisica con il legante geopolimerico. Nelle rocce carbonatiche si è invece osservata una parziale dissoluzione della calcite, legata al grado di cristallinità del carbonato, e conseguente diffusione di calcio nella matrice geopolimerica e formazione difasi di precipitazione. Fanghi di segagione della Pietra Serena sono stati impiegati anche come precursori nella sintesi di AAMs, valutando la possibilità di ottenere materiali per applicazioni strutturali a partire da materiale di scarto. I fanghi di segagione sono stati utilizzati tal quali o trattati termicamente a 800°C per 2 ore. Gli AAMs ottenuti hanno rivelato l’inefficienza degli scarti usati tal quali come precursore e la sua validità se usata calcinata a causa dello sviluppo di CaO e alla formazione di fasi C-S-H caratteristici dei materiali cementizi. Sono state inoltre valutate le caratteristiche di AAMs ottenuti da miscele di ceneri volanti, metacaolino e fanghi di segagione. Risultati promettenti in termini di valori di resistenza meccanica sono stati ottenuti per miscele binarie fly ash- fanghi di segagione di Pietra Serena.
Alkali activated materials (AAMs) are amorphous materials obtained by the reaction of an aluminosilicate source and an alkaline solution. AAMs, included those called geopolymers, are studied as alternative to traditional construction materials mainly for their versatility, high mechanical properties and durability. The research concerned the study of alkali activated binders, mortars, cements and composites, in order to assess their suitability in the construction field, especially for the conservation of existing materials belonging to Cultural Heritage, for which the use of versatile and high performance materials can be advantageous. The interaction and synergic use of AAMs with natural and artificial stone materials was also evaluated. Geopolimeric binders were obtained by using a high quality kaolin (kaolinite 73% and 27% quartz) heat-treated at 800°C for 2 hours and sodium silicate. Binders characterized by different water/solid weight ratios between 0.33 and 0.66 were synthesized, in order to obtain workable materials without the use of additives, and the role of water in the reaction development has been evaluated. High values of compressive and flexural strength (up to 72 MPa and 6 MPa, respectively) were obtained for all the samples. Increasing the water content an increase both of porosity (from 21% to 32%) and median pore radius were observed. Infrared spectroscopy allowed to correlate the degree of amorphous gel development with the water content increase. The results showed that the decrease of mechanical strengths have to be ascribed to the porosity increase rather than to the reduction of metakaolin conversion into geopolymer. The binder with a water/solid ratio of 0.66 was used for the synthesis of mortars, using two crashed ornamental stones, the Pietra Serena and the Pietra di Angera, as aggregates. The physical and mechanical characterization returned: i) mechanical strength values that fall within the M20 class (UNI-EN 998-2: 2010); ii) density values comparable to those of ornamental stones reference; iii) porosity values between 14 and 17%. In the mortar synthesized by using Pietra Serena the fine fraction seemed to contribute to geopolymeric reaction, providing soluble silica and alumina. Colorimetric measurements were also carried out on samples in order to evaluate the aesthetic compatibility of the mortars with ornamental stone references. The binder with a water/solid ratio of 0.46 was used to evaluate the interaction, at the interface, between geopolymers and natural (ornamental stones) and artificial (brick, mortar and concrete) stone materials, by performing stereomicroscope and SEM analysis. Results showed that the stone material compositions influenced the adhesion properties of geopolymers. An alumino-silicate matrix, like those of Pietra Serena and brick, seemed to have a greater physical affinity with the geopolymer binder. In the carbonate matrices instead a partial dissolution of calcite, related to crystallinity of calcite itself, and calcium diffusion into geopolimer matrix were observed giving rise to precipitation phases. Sewage sludge deriving by the cultivation of Pietra Serena were also used as precursors in the synthesis of alkali activated cements. Sewage sludge were used untreated or heat-treated at 800°C for 2 hours. The AAMs obtained by using a 8 M sodium hydroxide solution revealed the inefficiency as precursor of the untreated sludge (3 MPa of compressive strength), and its validity if used calcined (up to 18 MPa) due to the development of CaO and the formation of CSH phases characteristic of cement-based materials. The features of alkali activated cements obtained from mixtures of fly ash, metakaolin and sewage sludge was also evaluated. Results revealed promising mechanical strength values for binary mixtures fly ash - Pietra Serena sewage sludge.

Detection and identification of pesticide residues on objects of cultural heritage is a serious and urgent challenge that currently faces many museums, Native American communities, and private collections worldwide. Organic artifact materials, such as wood, animal hide, basketry, textiles, paper, horn and bone, have traditionally been treated with pesticides to eradicate and prevent infestation by insects, rodents, and mold. These poisonous substances can persist for years in the controlled environment of a museum storeroom and present a potential poisoning risk to people who come in contact with the objects. Surface-enhanced Raman spectroscopy (SERS) has the potential to detect volatile organic pesticides in this context. The technique can overcome the insensitivity of normal Raman spectroscopy and fluorescence interference, and make possible detection of many organic compounds in parts per million concentration. This investigation is aimed at evaluating SERS for the detection and identification of volatiles in museums, with emphasis on naphthalene vapor. The potential of several SERS-active materials; Tollens mirrors, gold film over nanosphere arrays, citrate-stabilized colloidal silver, and nanoporous gold; to detect Rhodamine B and naphthalene is investigated. The research also highlights the mechanisms that underlie SERS, and the relationship between substrate nanostructure and SERS performance.

The research presented in this dissertation covers three separate topics of conservation as defined by the National Science Foundation: 1) Materials Stabilization, Strengthening, Monitoring, and Repair; 2. Understanding Material Degradation and Aging; and 3) Materials and Structural Characterization of Cultural Heritage Objects (the `technical study'). The first topic is addressed through a study to assess the consolidant tetraethoxysilane for the stabilization of alum treated wood. Falling under materials degradation studies is a study published in American Museum Novitates to understand how environmental conditions affect the aging of fossil resins from five different deposits. Two separate studies are included in technical study of cultural heritage objects which comprises the third research area of materials characterization. The first is a survey of red dyes used in Chinese paintings from the Ming Dynasty to the Early Republic (1364-1911). The second is a study of the pigments, dyes and binders used in Hawaiian barkcloth (kapa) from the 19th century.

Iron-tannate dyes have been used for thousands of years and on many continents to colour materials that are now part of our cultural heritage shades of black, grey, or brown. Cellulosic and proteinaceous yarns and woven textiles have been dyed with iron-tannate dyes to form objects or components of objects for domestic and ceremonial use. Unfortunately, the longevity and useful lifetime of iron-tannate dyed objects is threatened by the dye itself which accelerates the degradation of organic materials through metal-catalysed oxidation and acid-catalysed hydrolysis. The accelerated degradation causes weakening, discolouration, and embrittlement of the organic materials at a faster rate than undyed equivalents and if left unimpeded, weakens the objects to the point that they are no longer able to be exhibited without damage. In some cases the degradation is so great that the dyed areas of the objects have crumbled to dust. At present there is no suitable chemical stabilisation method available with which to inhibit this degradation. An aqueous treatment is available for successfully stabilising paper containing iron gall ink; iron gall ink is chemically similar to iron-tannate dye. However, the aqueous nature of this treatment makes it unsuitable for weakened fibres, water soluble components, and water sensitive materials which may be part of a composite material containing iron-tannate dye. Non-aqueous treatments are therefore urgently needed in order to preserve our iron-tannate dyed cultural heritage for future generations.In this project a range of non-aqueous antioxidants and a non-aqueous deacidifier (described in Chapter 8) were tested alongside existing aqueous treatment in order to establish their ability to slow down the degradation of a range of model iron-tannate dyed textiles (Chapters 9 and 10). Model textiles were developed as part of the project (Chapters 3-5) to be substitutes for historic materials in these stabilisation studies. Validation of the model textiles for this purpose (Chapter 6) involved the comparison of the model textiles with selected historic iron-tannate dyed objects within the British Museum’s collection (Chapter 6). The historic objects and the properties of the model textiles before and after accelerated ageing (Chapters 5 and 6) and before and after treatment application (Chapters 9 and 10) have been characterised using a variety of analytical techniques (Chapter 2). In order to determine which accelerated ageing conditions were the most suitable for this project various combinations of elevated temperature and either cycling or stable relative humidity were tested for their ability to produce noticeable changes in the properties of the dyed model textiles within four weeks of ageing (Chapter 7). This project is an AHRC/EPSRC funded Science and Heritage Programme PhD in which the British Museum has been a collaborative institution. Among other wider dissemination methods, research from this project has been presented to the public on numerous occasions at gallery tours and Science Day events at the British Museum.

This thesis examines the preservation challenges heritage cities face because of climate change, with Venice as a case study and references to Rhodes Town, Edinburgh Castle, and Old San Juan. Dominant literature and scholarship on Venice compete with one another, restricting opportunities for interdisciplinary collaboration and dialogue in producing a more efficient preservation approach to the city. Through a study of the brief history of Venice, the materials, and past and present approaches to preservation, this research signifies the need to understand and preserve building materials. Following an analysis of the scholarship on Venice, this paper reveals the role of building materials in discourse on the city, as materials can bridge the gap among competing literature. Therefore, this thesis makes a key contribution to the understanding of urban history and preserving historic cities. In exploring preservation techniques and considering how the discourse can more effectively address the challenges of sea level rise of historic cities, this thesis argues the history of materials is key to a cohesive preservation approach for Venice's built heritage. The building materials are at the center of the preservation issue, and by serving as the core of dialogue and interdisciplinary collaboration, a more efficient approach to preserving the city's local and global heritage will occur. This thesis shows historic building materials can become central to Venice's preservation approach with increased vocal concerns about the building materials from restorers/conservators, non-governing residents, art historians, scientists, and global onlookers to Venice's local government, the Italian government, and international preservation bodies. In exploring preservation techniques and considering how the discourse can develop to address the challenges of sea level rise more effectively on historic cities, this thesis argues the history of materials is key to a cohesive preservation approach for Venice's built heritage. The building materials are at the center of the preservation issue, and by serving as the core of dialogue and interdisciplinary collaboration, a more efficient approach to preserving the city's local and global heritage will occur. This thesis shows historic building materials can become central to Venice's preservation approach with increased vocal concerns about the building materials from restorers/conservators, non-governing residents, art historians, scientists, and global on-lookers to Venice's local government, the Italian government, and international preservation bodies.
Master of Arts
This thesis examines the preservation challenges heritage cities face because of climate change, with Venice as a case study and references to Rhodes Town, Edinburgh Castle, and Old San Juan. Literature on Venice compete with one another, restricting opportunities for conversation on producing an efficient preservation approach to the city. Through a study of the brief history of Venice, the materials, and past and present approaches to preservation, this research signifies the need to understand and preserve the building materials. The role of building materials in discussions and debates on the city is necessary as materials can bridge the gap among competing literature. With building materials at the center of the preservation issue and the core of conversation among different disciplines, a more efficient approach to preserving the city's local and global heritage will occur.

Rising damp is an almost inevitable and hazardous phenomenon for historic buildings. This phenomenon, which already exists in buildings (to a lesser or greater extent), accelerates when faced with disasters that dramatically increase the water content within the building. While researchers are developing new monitoring methods to examine the effects of rising damp on structures effectively, organizations are designing new risk management plans to minimize the impact of disasters to which cultural heritages are exposed. The case study presented in this thesis includes studies carried out in the Byzantine church of Santa Croce in Ravenna, Italy, which was exposed to rising moisture from flooding due to soil submersion. By analyzing the samples collected from the church, the extent of the decay was determined. Moreover, a new method ensured that the monitoring of moisture in the church was reliable. The data obtained can be used to support the multi-disciplinary studies carried out in the church of Santa Croce, which was selected as part of the EU Horizon 2020 SHELTER project.

The aqueduct of Água da Prata has been amongst the most prestigious constructions of the XVI century in the city of Évora which has been declared as a World Heritage Site by UNESCO in 1986. The aqueduct itself has been classified as a National Monument in 1910 due to its patrimonial value and has been added to the ‘Watch List’ of the World Monuments Fund (WMF) in 2016 to promote the preservation and the monitoring of the cultural heritage. The aim of the work is to bring a clear understanding to the mortars of the aqueduct from a textural, mineralogical and chemical point of view to identify the different construction phases including the restorations and decorative interventions (ranging from the Roman period to XIX century), the technology used for their production and the origin of the raw materials. The results provide valuable information about the monument’s history by enlightening its Roman pre-existence and contribute to future restoration practices for the preparation of compatible repair mortars. A total of 20 mortar samples have been collected from the various sections of the aqueduct with different structural uses (filler and render) and examined by a multi-analytical approach by means of Optical Microscopy (Stereo zoom and Petrographic microscope), X-ray Diffraction (XRD), Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy (SEM-EDS), Thermogravimetric analysis (TGA-DTG), Acid attack and Granulometric analysis. The results revealed similar mineralogical compositions of the aggregates which are compatible with the local geology but distinctive binder properties based on their construction periods and different functional needs that are clayish binders with a small amount of calcitic lime, calcitic lime and dolomitic lime binders; RESUMO: Caracterização de Argamassas do Aqueduto da Água da Prata (Évora, Portugal) O aqueduto da Água da Prata é uma das mais prestigiadas construções do século XVI na cidade de Évora tendo sido classificado como Monumento Nacional em 1910 devido ao seu valor patrimonial. Em 1986 foi declarado Património Mundial pela UNESCO e em, 2016, integrou a lista de monumentos de interesse mundial com necessidade de preservação da World Monuments Fund (WMF), organização sem fins lucrativos e que promove o programa World Monuments Watch cuja finalidade passa por conservar a herança cultural em todo o mundo. O trabalho apresentado teve como objetivo a caracterização de argamassas do aqueduto do ponto de vista textural, mineralógico e químico, permitindo identificar as diferentes fases construtivas, a tecnologia utilizada para a sua produção e a origem das matérias-primas. Os resultados fornecem informações valiosas sobre a história do monumento, corroborando a sua pré-existência romana, e que contribuem para futuras práticas de reabilitação, nomeadamente, para a preparação de argamassas de reparação compatíveis com as existentes. Foram recolhidas 20 amostras de argamassas, em diferentes partes do aqueduto, e analisadas por uma abordagem multi-analítica: Microscopia Ótica (estereomicroscopia e petrografia), Difração de raios X (DRX), Microscopia Eletrónica de Varrimento – Espectroscopia de Energia Dispersiva de raios X (MEV-EDS), Análise Termogravimétrica (ATG-DTG), Ataque Ácido e Análise Granulométria. Os resultados revelaram que as argamassas estudadas são similares no que respeita aos agregados, compatíveis com a geologia local, mas com propriedades ligantes distintas, com base nas diferentes necessidades funcionais e temporais, nomeadamente ligantes argilosos com uma pequena quantidade de cal calcítica, ligantes de cal calcítica e ligantes de cal dolomítica.

La bio-détérioration des documents culturels compte parmi les types de détériorations les plus complexes que sont amenés à subir ces objets; et ce, parce qu’elle implique des organismes vivants ainsi que la conjonction de nombreux facteurs. Il existe différentes formes de biodétérioration; les taches de substrat (support?) engendrées par des champignons pigmentés en sont un exemple. Une multitude d’actions se développent aux “interfaces” entre le substrat (support?) et les champignons, depuis le premier contact avec les spores, en passant par la prolifération fongique, jusqu’aux interactions avec l’environnement. L’analyse multi-échelle et multisensorielle de l’interface entre les moisissures pigmentées noires et le support papier est le sujet de ces thèses. Deux types de pigmentations fongiques noires ont fait l’objet d’une analyse; la première apparaissait spontanément sur les œuvres d’art , la deuxième résultait d’une pigmentation déclenchée en biosimulation, sur des papiers connus, dans un environnement maitrisé. Les caractéristiques des papiers telles que le relief et la structure de la surface, la morphologie des champignons, les processus de dépôt de la biomasse pigmentée, ainsi que la prolifération fongique, ont fait l’objet de multiples examens, tant en termes d’instruments que de méthodes :microscopie à lumière transmise, microscopie électronique à balayage (MEB) dans une chambre à pression variable, microscopie confocale à balayage laser, profilomètre confocal à lumière blanche, microtomographie aux rayons L’objectif ultime étant de développer une stratégie de préservation des objets du patrimoine culturel bio-détériorés, le choix des instruments et des méthodes d’analyse était dicté par un souci pratique qui limitait l’échantilllonage des éléments analysés. Ce travail constitue une première tentative afin de mieux comprendre les forces en présence au niveau des “interfaces”, dans le cas des taches sur le papier dues aux champignons
Biodeterioration of cultural materials is one of the most complex types of deteriorations that cultural materials are subjected to mainly, because it involves living organisms and synergy of many factors. There are different forms of biodeterioration, stains of substrate caused by pigmented fungi is one of them. Multitude of events occurs at interfaces between substrate and fungi, from the moment of spores’ first contact with surfaces, next fugal growth and their responses to the environment. Multiscale and multisensory analysis of interfaces between black pigmented fungi and paper substrate was the subject of these theses. Two types of black fungal pigmentations were analyzed; one that occurred on the original artworks the other one was induced in biosymulation on known papers in controlled environment. Paper characteristics, such as surface topography and structure, morphology of fungi and patterns of their pigmented bio-mass deposition as well as fungal growth were examined with an array of analytical instruments and methods: transmitted light microscopy, scanning electron microscopy in variable pressure, confocal laser scanning microscopy, white light confocal profilometer and X-ray microtomography. The ultimate goal was to develop a preservation strategy for biodeteriorated cultural heritage material; therefore the choice of the analytical methods and instruments was dictated by real-life protocols that limit sampling of cultural materials. This works is the first attempt towards a better understanding of interfacial forces in fungal stains on paper

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Most of the features are displayed by complex organisms results of multifactorial inheritance, such as skin color in humans. This study aimed to investigate the high school students conceptions about multifactorial inheritance and, based on the information collected, develop educational materials that promote the application of genetic concepts in everyday matters. Participated in this study 48 students from two high school classes, enrolled in two public schools in Santa Maria / RS and São Vicente do Sul / RS. The survey was conducted in three stages called application of pre-test, didactic approach and implementation of the post-test. We develop a game, a didactic model and a hypertext is recommended for high school classes. The game and the teaching model was applied by the researcher and indicate their use for classes that have studied basics of monogenic and multifactorial inheritance. The applied materials were evaluated as motivation and use of genetic concepts. The evaluation by students and teachers indicated that the proposal is challenging and useful for genetic education with good applicability to review concepts. Hypertext was developed in three versions, according to the student's reality, being a material useful for situations where you have little time to teaching content to be a practical and easy handling means. To make it more interesting and interactive activity is recommended to be done beyond reading a discussion so that students and teachers can share ideas on the subject under study. Students from both groups showed an increase in the proportion of correct answers after the application of the didactic sequence, this improvement was most notable for the students in the class had a low rate of correct answers in the pre-test which had not studied the subject multifactorial inheritance ( class 2).
A maioria das características apresentadas pelos organismos complexos são resultados de heranças multifatoriais, como por exemplo, a cor da pele nos seres humanos. Este trabalho teve como objetivo investigar as concepções de alunos do Ensino Médio sobre herança multifatorial e, com base nas informações coletadas, desenvolver materiais didáticos que favoreçam as aplicações de conceitos de genética em assuntos do cotidiano. Participaram deste trabalho 48 alunos de duas turmas de Ensino Médio, matriculados em duas escolas públicas localizadas em Santa Maria/RS e São Vicente do Sul/RS. A pesquisa foi realizada em três etapas denominadas aplicação do pré-teste, abordagem didática e aplicação do pós-teste. Desenvolvemos um jogo, um modelo didático e um hipertexto sendo recomendados para turmas de Ensino Médio. O jogo e o modelo didático foram aplicados pela pesquisadora e indicamos a sua utilização para turmas que já estudaram conceitos básicos de herança monogênica e multifatorial. Os materiais aplicados foram avaliados conforme motivação e utilização de conceitos de genética. A avaliação por alunos e professores indicou que a proposta é desafiadora e útil para o ensino de genética, com boa aplicabilidade para revisar conceitos. O hipertexto foi desenvolvido em três versões, de acordo com a realidade do aluno, sendo um material útil para situações em que se tenha pouco tempo para o ensino do conteúdo por ser um meio prático e de fácil manipulação. Para tornar a atividade mais interessante e interativa recomenda-se que seja feita além da leitura uma discussão para que os alunos e professor possam compartilhar ideias sobre o tema em estudo. Os alunos de ambas as turmas apresentaram aumento na proporção de respostas corretas após a aplicação da sequência didática, essa melhora foi mais notável para os alunos da turma que teve baixo índice de acertos no pré-teste a qual não havia estudado o tema herança multifatorial (turma 2).

This thesis examines protection against risks as material and social phenomena among the Ammarin tribe in Petra – a settled Bedouin community in southern Jordan. By examining the active role of material culture that is often disregarded in risk studies, the thesis discusses how protective strategies are entangled in cultural, religious, and national identities. Using ethnographic methods, I investigate protection against selected risks: harm from evil eyes, violation of domestic sanctity, and cultural heritage dilapidation. Protection against these risks is examined through studies of architecture, the social use of luminosity, prophylactic items, saint veneration, Qur’anic items, and heritage production. The thesis challenges the preoccupation with “meaning” in material culture studies, by focusing on conceptualizations of “presence” and “absence” as equally important to protective efficacy. Some informants, for example, adopt an orthodox scriptural Islamic approach to protection and denounce certain material registers as un-Islamic and materialistic leftovers from an ignorant past, and rather prescribe Qur’anic remembrance. For other informants the very physicality of such contested strategies are confirming their efficacy, and act as material anchors for negotiating Bedouin identities in response to a rapid transformation from nomadic pastoralists to sedentary wageworkers. The tensions surrounding the materiality of protection, along with the role of the past in the present is further investigated through the contested public representations of Ammarin culture, along with a detailed study of the process leading to the protection of Bedouin culture by UNESCO Intangible Cultural Heritage. The overall conclusion of this research is that negotiating efficacious protection against perceived risks, is about actively taking a stance on senses of exposure, vulnerability and uncertainty towards the people, places and things that are cherished. These strategies simultaneously act as potent public exposure of social, religious, and national moral identities that may empower, exclude, or ostracize people.

Every investigation technique has its specific advantages: this is the reason why, in modern research, it is common to combine many investigation techniques – especially the non-destructive ones - to achieve deeper structural information about a sample. X-ray diffraction (XRD) and fluorescence (XRF) techniques are useful non-destructive analytical techniques, with applications not only in industrial field and mining but also in environmental control and cultural heritage monitoring and conservation. In the present research, the advantages of a combined approach with XRF and XRD techniques are considered, due to their complementarity, and a new method of combining data is presented, executing the simultaneous computation of the refinement both for XRF and XRD. In this case, instead of the common approach with an iterative refinement, passing from XRF to XRD and vice versa, both XRF and XRD data are processed simultaneously with a combined Rietveld refinement. This innovative approach has been implemented in the program MAUD, combining original XRD algorithm with the XRF module implementation from the GimPy and JGIXA programs, creating comprehensive radiation–matter interaction model, which takes care of both elastic scattering and photoelectric absorption/fluorescence. Moreover, through a plugin-based application container, Eagle-X, specifically developed for this research project, some easy external wizards have been developed using JAVA language for preliminary XRF analysis and model set-up, which will be in the next future integrated into the MAUD current interface. This new approach has been applied to two case studies. The first study was in the cultural heritage field with the analysis of ancient Venetian coins, called sesini, which were never investigated before. These coins were widely used in the Venetian Republic over a time span ranging from the second half of the 16th until the early years of the 17th century. The rationale of the study was to establish a multilayer model that once validated could be used for fully non-destructive characterization of similar items. The approach, applied to 20 samples from different time periods, has given interesting results. First, the actual composition of the copper-based alloy used for these specific types of Venetian coin has been measured for the first time, using a three-layer model, with also direct measurements on the coin cross-section for validating the data obtained. Second, the detailed characterization of the coins provided essential background knowledge for fully non-destructive characterization of the same kind of coins. Third, the data obtained were very interesting from a historical point of view, because the silver depletion, which this research has investigated over the coin series, reflects a political and economic situation in strong evolution for the Venetian Republic in the second half of 16th century. Political and economic competitors and a continuous effort in military confrontations obliged Venice to revise its coin system and values not only for sesini but also for the other silver-based coins, with larger value, in a process called debasement. The second application of the combined approach regarded an industrial application concerning a sintered titanium alloy, Ti6AlV4, that has the widest use (about 45% of the total production), because of good machinability and excellent mechanical properties. This is an alloy which contains the two allotropic forms of Ti, the Ti-alpha, which has compact hexagonal cell, stable at room temperature, and Ti-beta phase, which has a body-centred cubic lattice, stable over 882°C. The presence of the two phases is related to the presence of atomic elements which are alpha- and beta-stabilizers. In this case study six samples, produced with Selective Laser Melting (SLM) technology, with different production parameters, has been considered, and a model based on a surface layer of compact oxide and a bulk with the alloy only has been adopted. The model has evidenced the presence of the TiO2 oxide on the surface, as attended from existing literature, and confirmed the quality of the alloy because for all the samples, the investigated areas report Al e V content inside the ranges required by ASTM and ISO specifications. The analysis has allowed also to investigate the presence of contaminants like copper due to the cutting process by Electrical Discharge Machining (EDM), and to find a correlation between the content of Ti-beta phase inside the samples and the combined presence of iron and silicon, which increases as soon as increase also the two elements. Moreover, the increase of Ti-beta phase is boosted by the contemporary increase in energy density during SLM production process. This is consistent with the fact that higher energy allows a higher localized temperature in SLM process and the equilibrium fraction of beta phase rises at high temperatures. This then leads to a higher fraction of alpha+beta phases at room temperature and, because the cooling rate was the same for all samples, this means a higher fraction of  phase at room temperature. The application of the technique to the two case studies is very productive from the informational point of view, but a critical aspect for a successful application of the technique is the sample. No preparation is virtually needed for analysis but, of course, this is immediately true for industrial components as soon as they are produced, but it is not so true for archaeological artefacts, where the condition of production, history and store conditions are unknown. Corrosion patinas can alter the read of the data, and some care must be taken for analysis, not only because the patinas may not be homogenous, but also because the depth of penetration for XRF and XRD are not the same, respect to the same substrate. The cleaning of the artefacts is not always possible or desired by the owners, so this can at first stage complicate the approach to combined analysis, regarding the model to be adopted in material simulation for data interpretation. In any case, the combined analysis remains a valid approach provided that the user is conscious of the limits in terms of depth of analysis, linked to the analysis tool (X-ray beam, detector, etc…) and to the surface conditions of the sample.

Every investigation technique has its specific advantages: this is the reason why, in modern research, it is common to combine many investigation techniques – especially the non-destructive ones - to achieve deeper structural information about a sample. X-ray diffraction (XRD) and fluorescence (XRF) techniques are useful non-destructive analytical techniques, with applications not only in industrial field and mining but also in environmental control and cultural heritage monitoring and conservation. In the present research, the advantages of a combined approach with XRF and XRD techniques are considered, due to their complementarity, and a new method of combining data is presented, executing the simultaneous computation of the refinement both for XRF and XRD. In this case, instead of the common approach with an iterative refinement, passing from XRF to XRD and vice versa, both XRF and XRD data are processed simultaneously with a combined Rietveld refinement. This innovative approach has been implemented in the program MAUD, combining original XRD algorithm with the XRF module implementation from the GimPy and JGIXA programs, creating comprehensive radiation–matter interaction model, which takes care of both elastic scattering and photoelectric absorption/fluorescence. Moreover, through a plugin-based application container, Eagle-X, specifically developed for this research project, some easy external wizards have been developed using JAVA language for preliminary XRF analysis and model set-up, which will be in the next future integrated into the MAUD current interface. This new approach has been applied to two case studies. The first study was in the cultural heritage field with the analysis of ancient Venetian coins, called sesini, which were never investigated before. These coins were widely used in the Venetian Republic over a time span ranging from the second half of the 16th until the early years of the 17th century. The rationale of the study was to establish a multilayer model that once validated could be used for fully non-destructive characterization of similar items. The approach, applied to 20 samples from different time periods, has given interesting results. First, the actual composition of the copper-based alloy used for these specific types of Venetian coin has been measured for the first time, using a three-layer model, with also direct measurements on the coin cross-section for validating the data obtained. Second, the detailed characterization of the coins provided essential background knowledge for fully non-destructive characterization of the same kind of coins. Third, the data obtained were very interesting from a historical point of view, because the silver depletion, which this research has investigated over the coin series, reflects a political and economic situation in strong evolution for the Venetian Republic in the second half of 16th century. Political and economic competitors and a continuous effort in military confrontations obliged Venice to revise its coin system and values not only for sesini but also for the other silver-based coins, with larger value, in a process called debasement. The second application of the combined approach regarded an industrial application concerning a sintered titanium alloy, Ti6AlV4, that has the widest use (about 45% of the total production), because of good machinability and excellent mechanical properties. This is an alloy which contains the two allotropic forms of Ti, the Ti-alpha, which has compact hexagonal cell, stable at room temperature, and Ti-beta phase, which has a body-centred cubic lattice, stable over 882°C. The presence of the two phases is related to the presence of atomic elements which are alpha- and beta-stabilizers. In this case study six samples, produced with Selective Laser Melting (SLM) technology, with different production parameters, has been considered, and a model based on a surface layer of compact oxide and a bulk with the alloy only has been adopted. The model has evidenced the presence of the TiO2 oxide on the surface, as attended from existing literature, and confirmed the quality of the alloy because for all the samples, the investigated areas report Al e V content inside the ranges required by ASTM and ISO specifications. The analysis has allowed also to investigate the presence of contaminants like copper due to the cutting process by Electrical Discharge Machining (EDM), and to find a correlation between the content of Ti-beta phase inside the samples and the combined presence of iron and silicon, which increases as soon as increase also the two elements. Moreover, the increase of Ti-beta phase is boosted by the contemporary increase in energy density during SLM production process. This is consistent with the fact that higher energy allows a higher localized temperature in SLM process and the equilibrium fraction of beta phase rises at high temperatures. This then leads to a higher fraction of alpha+beta phases at room temperature and, because the cooling rate was the same for all samples, this means a higher fraction of  phase at room temperature. The application of the technique to the two case studies is very productive from the informational point of view, but a critical aspect for a successful application of the technique is the sample. No preparation is virtually needed for analysis but, of course, this is immediately true for industrial components as soon as they are produced, but it is not so true for archaeological artefacts, where the condition of production, history and store conditions are unknown. Corrosion patinas can alter the read of the data, and some care must be taken for analysis, not only because the patinas may not be homogenous, but also because the depth of penetration for XRF and XRD are not the same, respect to the same substrate. The cleaning of the artefacts is not always possible or desired by the owners, so this can at first stage complicate the approach to combined analysis, regarding the model to be adopted in material simulation for data interpretation. In any case, the combined analysis remains a valid approach provided that the user is conscious of the limits in terms of depth of analysis, linked to the analysis tool (X-ray beam, detector, etc…) and to the surface conditions of the sample.

2016 - 2017
In this project, the attention has been focused on the laser ablation process and on laser induced plasmas spectroscopic study for two different technological applications. First of all, the analytical LIBS (Lase Induced Breakdown Spectroscopy) technique, which allows to obtain qualitative and quantitative information on the elemental composition of the materias analyzed, has been used and developed. The LIBS has been applied to the study of bronze and silver archaelogical findings, coming from three different sites in Basilicata and dated VI century B.C.. The inverse Calibration Free method, that is new a method, that is new a method of quantitative analysis, has been optimized. … [edited by Author]
XXX ciclo

Made available in DSpace on 2016-04-25T20:20:22Z (GMT). No. of bitstreams: 1 Maria Amelia Jundurian Cora.pdf: 2479891 bytes, checksum: 2dc34be1ee9faf8bc8b1723496bf8d2a (MD5) Previous issue date: 2011-08-02
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Created in 2000, the Programa Nacional do Patrimônio Imaterial (PNPI) National Program of Intangible Heritage established a new form of state action related to Brazilian intangible heritages. Executed by Instituto Nacional do Patrimônio Nacional (Iphan), the program innovates by extending its object of heritage, by proposing the registration process for intangible cultural heritage and the development of safeguarding plans to determine the actions to be undertaken. The central problem is based on the following questions: a) what were the progresses and limitations of the Programa Nacional do Patrimônio Imaterial (National Program of Intangible Heritage); b) how its establishment has impacted on the Brazilian cultural policy and the dynamics of cultural property registered as Patrimônios Culturais do Brasil (Cultural Heritage of Brazil)? Based on these questions, this research aims at understand how was the process of implementation of PNPI. The research is based on the analysis of procedures for registration and documents provided by Iphan on its website, supplemented by interviews with Iphan technicians, cultural intermediaries and holders of registered cultural property. It was observed that despite its progress, the program still needs to publicize its procedures and purposes, as well as to increase its human and financial resources to meet the demands created by the program itself. In the context of the holders of cultural property, was noticed that those who obtained record make use of the title Cultural Heritage of Brazil to achieve specific benefits such as access to social rights, the possibility of generating employment and income, partnerships, brokering with other public officials, etc. That is because the title gave greater visibility to the registered holders of cultural practices, enabling better articulation of them
Criado em 2000, o Programa Nacional do Patrimônio Imaterial (PNPI) estabeleceu uma nova forma de atuação do Estado em relação aos patrimônios imateriais brasileiros. Executado pelo Instituto Nacional do Patrimônio Nacional (Iphan), o programa inova ao ampliar seu objeto de patrimonialização, propondo o processo de registro de bens culturais imateriais e a elaboração de planos de salvaguarda para determinar as ações a serem realizadas. O problema central baseia-se nas seguintes indagações: a) quais foram os avanços e as limitações do Programa Nacional do Patrimônio Imaterial; b) como sua implantação impactou na política cultural brasileira e na dinâmica dos bens culturais registrados como Patrimônios Culturais do Brasil? Partindo desses questionamentos, esta pesquisa tem como objetivo geral compreender como se deu o processo de implantação do PNPI. A pesquisa é fundamentada na análise dos processos de registro e dos documentos disponibilizados pelo Iphan em seu sítio eletrônico, complementada pelas entrevistas realizadas com técnicos do Iphan, intermediários culturais e detentores dos bens culturais registrados. Observou-se que apesar dos avanços o programa ainda precisa publicizar seus procedimentos e finalidades, além de aumentar seus recursos humanos e financeiros para atender às demandas criadas pelo próprio programa. No âmbito dos detentores dos bens culturais, o que se percebeu foi que aqueles que obtiveram registro fazem uso do título de Patrimônio Cultural do Brasil para alcançar benefícios pontuais como acesso aos direitos sociais, possibilidade de geração de trabalho e renda, formação de parcerias, intermediação com outros agentes públicos etc. Isso porque o título proporcionou uma visibilidade maior para os detentores das práticas culturais registradas, possibilitando uma maior articulação dos mesmos. Palavras chave: Iphan, Patrimônio imaterial, Programa Nacional Patrimônio Imaterial, Patrimônio Cultural do Brasil

‘Millscapes’ is a heritage story that examines what heritage does. It sits within the field of critical heritage studies, drawing on the framework of New Materialism to explore how place and its inhabitants are entangled, materially, culturally and historically, within the Queensland wool textile industry. Its focus is the Queensland Woollen Manufacturing Company (QWMC), a state heritage-listed site situated in Ipswich, a satellite city of Brisbane, Queensland, Australia. Little has been written about the woollen mills apart from newspaper accounts, meaning that the significance of the woollen textile industry for Ipswich and Queensland is little known and understood. The study is timely for the QWMC site as it was purchased in 2015 by Ipswich City Council and is undergoing conservation works. The future use of the site is yet to be determined. The questions of what this heritage does are examined through exploring the mill site’s territorialities and flows of affect, and the intra-actions between machines, operators, mill management structures and entanglements with families and communities. Findings also emerge on the ways in which New Materialism brings understandings of the becoming of this heritage, and cultivates new heritage research methods. By focusing on the last decades of QWMC (1947–1971), the research revisits times of extraordinary social change for the predominantly female workforce, in parallel with the global forces acting on the textile industry. The ‘Millscapes’ research can be regarded as a ‘re-turn’. It is not just revisiting the past but turning it over, revitalising understandings of woollen textile manufacturing in Queensland. New Materialism emphasises the material elements of the social (Fox & Alldred 2018b) and in doing so provides game-breaking insights to the field of heritage studies. The ‘New’ in New Materialism refers to a newness in thinking, deliberately setting aside hierarchical and a priori logic to rethink relationships and ontologies (St Pierre, Jackson & Mazzei 2016, p. 100). In this way, New Materialism breaks down binaries, decentring the human. Agency becomes performative and not necessarily human (Barad 2007). The non-linearity of causation is created by flows of affect (DeLanda 2015, p. 17), also reflected in the intra-actions between material and living entities (Barad 2007). Over a decade ago, Coole and Frost (2010) noted New Materialism’s newness, as indicated by a lack of agreed labelling. Since then, a proliferation of terms used within the New Materialism framework underline what Kuhn (1970) would identify as a revolutionary state of this school of thought. Through the conceptual and theoretical resources of New Materialism, ‘Millscapes’ demonstrates what heritage can do with a site in its raw state: it is not about adaptive re-use or creating a museum. Rather, it reflects the entanglement of place, space, bodies, presences, absences, atmospheres and memories held within the space – particles in suspension that move, collide, bond and come apart. Components intra-act, affect, change. The research events disrupt the past; memories leap across time to the present becoming enfolded with other matter through the plurality of site histories, ethnographies, walkthroughs, archival documents and photographs. The knowledge gained through my own learning about wool and fibre arts brought insights into the manufacturing processes. Field trips contextualised the mill with other remaining mill structures, the Queensland sheep industry and new start-up mills. Concepts, methodologies and findings merged. Data created interpretation, which created data. Heritage became iterative acts, bringing the past to the present and drawing in future potentialities, significantly shifting perspectives and boundaries. The performativity of heritage emerged through different materialities as I walked the mill site, studying the photographs and prompting workers’ rememberings. Memories pushed through, energised by their affective intensities. Stories voiced by former workers intermingled with observations of the heritage site and remnant matter. Spatial memories were drawn to life and the site’s possibilities imagined. The New Materialism framework generated rich, but often overwhelming, historical and experiential data offering a kaleidoscope of views. Each ‘twist’ could bring a movement of time, a movement through space as bodies emerged and receded within the scope yet remained enfolded within a larger account. As I struggled to analyse the data without disturbing its inherent entangledness, I was pushed to develop visualisation tools to examine intra-actions, the power dynamics through re/deterritorialisation and the interplay of materiality and expression. These tools are embedded with the findings of bringing a New Materialism perspective to this heritage. A key outcome of the research has been to understand the mill heritage as a process of intra-action: ongoing transformation through relationships. The research found stories of working conditions and the roles of women and girls at the mill entangled with social expectations around work, marriage and pay inequalities. These factors were further enmeshed with industrial manufacturing processes and practices – and, of course, the materiality of wool, always entangled, tough yet fragile. Unknown elements of the mill surfaced, through the intermingling of participants’ drawings, interior photographs and mill spaces, locating machinery in the empty spaces and clarifying the mill processes. Bringing agency to the non-human shifted knowing. As discussed in this thesis, operating a machine becomes contingent upon intra-actions between operators’ skills, behaviours, memories, machine capabilities, wool behaviours and the mill environment. Intra-action gives rise to considering what is shared and how components change through relationship. Power emerged as a back and forth of territorialisations, as millworkers found ways to get through the day. Gendered roles, although entrenched within social and organisational structures, could nevertheless change, both slowly and suddenly. What does heritage do? It remakes our understanding of our place in the world. A heritage policy framework can narrow the view of heritage around sites, building fabric and aesthetic, leaving behind important matter that resides mostly in memories. ‘Millscapes’ troubles the Authorised Heritage Discourse (AHD) (Smith 2006) as well as decentring the human in productive ways. Cultural heritage simply becomes heritage, as the lines between nature and culture blur, the global becomes enfolded in the local, and the industrial re-blends into the city’s commercial centre – once distant, now engulfed. In this account, humans are no longer assumed to be the centre of the story – they are not the only actants with agency. The myriad human and non-human components of the mill assemblage change at different speeds and intensities. Importantly, this work has potential for informing strategies for heritage management and processes to determine heritage significance – moving beyond a values-based approach. The statement of significance in the state heritage register is wanting in terms of social and industrial significance. Understanding what heritage does and what this site does provides a refreshing view. New Materialism calls attention to the generative nature of the heritage and an understanding of the whole assemblage. The mill assemblage is dynamic, not static – not something that is or was, but a place constantly being remade (even if imperceptibly). The process of research with in-situ activities opened the doors of the mill to the communities connected with it. This reach into community can be extended further.These connections enrich what the heritage does, our understandings of it; they recognise the shared responsibilities and the place’s ongoing becoming. This research attends to the multi-scalar dimensions of change across time, space, and matter: different times, different places, different people. Giovannelli’s cantata, quoted below, weaves the threads of three generations of women entangling handcrafting, manufacturing, and writing. This dissertation attempts a similar movement. The challenge of this work has been more than the writing of a doctoral thesis. Its findings are not only academic; they are also material, personal, creative. Through this work, we can show how the constant churn of matter brings a renewed ethics that highlights coexistence, our shared responsibility for our heritage and what it helps us to make out of the past and for the future. Heritage thus becomes a ‘making with’, a continual intra-action, a making and remaking of our world. The act of turning over and rearranging the folds of matter, space and time allows the becoming of something new. I, lost in a reverie on the shore / of an age old sea / holding a pen / but sharing the looms same lot / of interwoven strands and lives / a thread running through a century / of knots and invisible mends / the always threatening scissors / in your sewing basket, with its apotropaic stones/ and a piece of work in progress. My first time visiting the mill site was a Saturday afternoon, quiet, steamy, the mauve of a young jacaranda nicely lending its hues to frame my photograph. Peering through the chain wire fence didn’t give me any sense of what lay inside – just an old factory becoming derelict. The buildings, a forlorn presence on the street, were nothing grand, no indication of what it had been – just insignia on the gates QWM: Queensland Woollen Manufacturing – but you would need to know that. In a different space-time, a weekday in the 1960s, the milieu of the working mill, the loud rhythmic sound of shuttles flying across rooms paused each day with the ‘knock-off’ siren. A local had told me about afternoons back then, out on the verandah across the road, listening for that siren, the street filling with bicycles, and buses and young women pouring out of the mill. Another spacetime leap to wintery Saturdays, The Terrace vibrating with the surge of footy crowds, their team loyalties worn on scarves and beanies, made from real wool.The quietness today made me conscious of the whir of my snapping camera, even my presence in the street interrupted the residential ambience. This old mill was a building becoming heritage ...
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Hum, Lang & Soc Sc
Arts, Education and Law
Full Text

This research attempts to describe the material culture of the Gaelic labouring classes living in western Ulster in the Late Medieval period. The research combines ethnohistorical contextual and technical scientific analysis of ‘chance’ finds discovered in the region’s bogs. Technical analysis dates fifteen museum objects, characterises the materials from which they were made, and explores their cultural significance. Absolute dating indicates that one third of the 15 objects analysed relate to the Gaelic lordships of late medieval western Ulster, with the remainder reflecting aspects of Iron Age and Post-Medieval material culture and related cultural pracrices. Contextual analysis of the later medieval objects and their find locations provides new insights into Gaelic Irish culture and landscape interactions in this period and place. In addition, the research explores the trajectory of indigenous materiality in western Ulster beyond the Late Medieval period. To this end, the thesis examines the relationship between Late Medieval indigenous materiality, and the folk material culture that emerges in western Ulster in the Modern period.
Heritage Consortium, Arts and Humanities Research Council (UK)

The guiding thread of the research is testing biopolymers-based treatments for the protection of stone in cultural heritage against water and salt crystallization. The idea developed is that the reversibility requirement can be fulfilled by bio-polymeric treatments, owing to a “reversibility by biodegradation” once their efficacy has finished. The first part aimed at investigating the performance of two poly(hydroxyalkanoate)s-based (PHAs-based) formulations, namely solutions of poly(3-hydroxybutyrate (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxyvalerate) (PHBVV), as hydrophobic coating. These formulations were applied to sandstone, limestone and marble, in order to investigate their behaviour on different substrates. Their effectiveness and compatibility were evaluated and the samples wettability after application of biopolymers and of two commercial products was compared. Promising results in terms of efficacy and compatibility were obtained, although the present PHAs-based formulations still need improvement to increase their durability and on-site applicability. Among the strategies proposed to mitigate the damage caused by salt crystallization, the modification of the surface of the pore wall, by means of a polymer coating able to minimize the repulsive disjoining force normally acting between the stone and the crystallizing salt, is particularly promising. Thus, some polyectrolyte biopolymers (alginic acid sodium salt, chitosan and tannic acid) were selected and compared with a polymer (polyacrylic acid sodium salt) for preliminary screening tests, designed and performed in order to assess whether the selected polymers fulfil some basic requirements such as good adsorption onto the stone substrate, film-forming ability, affinity and interaction with sodium sulfate. Moreover, in order to reduce calcite dissolution in water that may trigger the effect of the polymer coating, a diammonium hydrogen phosphate (DAP) water-based treatment was applied as coupling layer on carbonate substrates. Then, the effectiveness of the coatings was evaluated by two macroscale crystallization tests on limestone with promising results especially for chitosan and alginic acid coupled with DAP.

Anthropology
Ph.D.
"Materializing Blackness: The Politics and Production of African Diasporic Heritage” examines how intellectual and civic histories collide with the larger trends in the arts and culture sector and the local political economy to produce exhibitions at the African American Museum in Philadelphia (AAMP) and structure the work that museum exhibitions do to produce race visually for various audiences. Black museums are engaged in the social construction of race through their exhibitions and programs: selecting historical facts, objects and practices, and designating them as heritage for and to their audiences. In tracking this work, I am interested in 1) the assemblages of exhibits that are produced, as a function of 2) the internal logics of the producing institutions and 3) larger forces that structure the field as a whole. Looking at exhibits that engage Blackness, I examine how heritage institutions use art and artifacts to visually produce race, how their audiences consume it, and how the industry itself is produced as a viable consumptive market. Undergirded by the ways anthropologists of race and ethnicity have been explored and historicized race as a social construction I focus on an instantiation of the ways race is constructed in real time in the museum. This project engages deeply with inquiries about the social construction of race and Blackness, such as: how is Blackness rendered coherent by the art and artifacts in exhibitions? How are these visual displays of race a function of the museums that produce them and political economy of the field of arts and culture? Attending to the visual, intellectual, and political economic histories of networks of exhibiting institutions and based on ethnographic fieldwork in and on museums and other exhibiting institutions, this dissertation contextualizes and traces the production and circulation of the art and artifacts that produce the exhibitions and the museum itself as a way to provide a contemporary concrete answer. Overall “Materializing Blackness” makes the case for history and political economy as ghosts of production that have an outsized impact on what we see on exhibition walls, and are as important to the visual work as a result. Further it takes the Black museum as a site of anthropological engagement as a way to see the conjuncture of the aesthetic and the political, the historical and the material in one complicated node of institution building and racecraft in the neoliberal city.
Temple University--Theses

Sunlight in an appealing energy source exploitable for a sustainable and equal development of human society, being abundant, widespread and cheap, on a scenario of adaptation strategies for facing the climate change happening on Earth surface. Several kind of chemical reactions required to sustain the society, from fuel production to environmental remediation, can be potentially run exploiting the light as energy source. A light-activated catalyst (photocatalyst) is often needed to allow such reactions to occurs, able to both absorb the photons and decrease the kinetic barrier. The aim of this work was to prepare some earth-abundant oxide-based semiconductor (SC) materials and assessed them in some photocatalyzed reactions, using a selected SC for each process. Titanium dioxide (TiO2) was used for H2 production from biomass, zinc oxide (ZnO) and a mixed iron-copper oxide (CuFeO2) in CO2 photoreduction, while a calcium-based plaster (marmorino) modified with TiO2 and ZnO, was used in cultural heritage photoremediation (self-cleaning). Different characterization techniques were exploited to achieve a comprehensive knowledge of structural, morphological, optical and surface properties of the prepared materials. Finally, the physical-chemical properties of these oxides were correlated to the photoactivity, aiming to understand how these features affect, negatively or positively, the performances of a given reaction.

This thesis studies contemporary China's heritage boom phenomenon as experienced through the everyday lives of antiquarian communities (collectors, antique dealers etc.) and heritage professionals in and around Beijing. Aiming to extend our vision beyond heritage sites and museums, which constitute the traditional subject of anthropological studies of heritage, the thesis explores the ways in which 'heritage' and 'treasure' are lived by wider Chinese urban residents, constituting a total social fact. Challenging the popular assumption made by heritage scholars in which heritage phenomenon is considered a by-product of modernity's tendency to contrast the current progress with the past as a benchmark, this thesis argues that contemporary China's heritage fever is, however, a social symptom of utopian replacement, in which the idea of linear progress promised by modernisation has been challenged by a recent nationwide utopian project of returning to 'the prosperous age' ('shengshi') with its emphasis on cyclical 'rise and fall'. Treasures of China, as 'Fragments of the Prosperous Age', have thus emerged as powerful imaginaries and resources to open up a utopian vision of ideal society based on fantastic imaginations of China's past glories. Foregrounding the relations between heritage and utopianism, the thesis subsequently investigates the complex ways in which heritage activists from state systems and antiquarian communities contribute to the utopian project from different pathways, bifurcating China's heritage phenomenon into formal and informal parts. Chapters one and two demonstrate that state-led imaginings have changed from the evolutionary perspective to one pursuing the glory of the past under the new spell of 'civilisational revival'. Officials and activists associated with formal heritage deploy a variety of discursive and bureaucratic technologies to securitise, manage and utilise China's ancient treasures, so as to legitimise the current regime. On the other hand, Chapters three and four show that collectors associated with informal heritage encounter fragments of the past in a bodily and joyful way. In ordinary antiquarian practices which juxtapose the cultivation of moral self with the patination of antique objects, collectors pursue an archaic yet neoliberal custodianship which has altered the ethics and sense of moral responsibility in the domains of market exchange. These two factions in China's heritage world may differ from each other in many aspects, but Chapter five suggests both of them, in fact, conspire to reproduce ancient 'prosperous age' ('shengshi') in the present and for the future. The thesis concludes with a discussion about the extent to which Hegel's future-oriented conception of 'capitalised History' that structures the writing of national history has transformed into a 'capitalised Heritage' in contemporary China. 'Capitalised Heritage' works to recast the importance of the Chinese nation in the contemporary world, reaching an ultimate reconciliation with the spectre and material legacies of the past.

As argamassas de fachada protegem a edificação, seu conteúdo e revelam sua identidade, funções realçadas quando se trata de patrimônio histórico. Elas sofrem pelo intemperismo, umidade, vandalismo, intervenções malsucedidas e vícios de fabricação. A tese apresenta e aplica uma metodologia de levantamento de danos, materiais e técnicas construtivas, para a conservação ou restauro de argamassas de fachadas históricas. Revisa a literatura de preservação arquitetônica e demonstra a importância desse levantamento. Faz uma compilação dos mecanismos de degradação de argamassas históricas. Traz informações práticas sobre acesso vertical à fachada, definição de objetivos de levantamento, representação da evolução histórica, elaboração de formulários de campo e orçamento. Apresenta proposta de formação de inspetores, revisa a bibliografia e propõe metodologia de levantamento de danos, materiais e métodos construtivos. No levantamento de danos, emprega a inspeção visual e ensaio não destrutivo, por percussão com martelo de bordas em ABS. Revê e propõe critérios de amostragem e protocolos de análises laboratoriais. Emprega análise macroscópica, difração de raios-X (DR-X), petrografia e química por digestão ácida. Traz sugestões quanto à síntese e apresentação dos resultados à equipe de restauração. A metodologia prima pela simplicidade e economicidade, foi desenvolvida através de três estudos de caso, sendo dois no Paço de São Cristóvão Pátio Maior e na fachada principal - e a fachada exterior do futuro Museu da Casa da Moeda do Brasil, ambos no Rio de Janeiro, juntos somando aproximadamente 4.400m² de argamassa. As informações de materiais e métodos construtivos contribuíram para o levantamento histórico e compreensão da patologia. O levantamento de danos por percussão indicou 69% de argamassa comprometida (problemas de aderência ou reposição inadequada) no Pátio Maior, apesar da inspeção visual indicar somente 5% de ausência de argamassa por queda. A demolição cuidadosa das argamassas degradadas comprovou um desvio de apenas 4% do levantamento de danos por percussão. O protocolo de análise laboratorial agrupou as amostras pela inspeção macroscópica e/ou DR-X, realizando análises mais completas apenas em representantes destes grupos. Empregou a DR-X na identificação mineralógica. A petrografia foi muito versátil, agregando informações sobre composição mineralógica, granulometria, porosimetria, traço aproximado e história geológica. O traço foi avaliado através da análise química, comprovada para argamassas de areia, cal e/ou cimento, entretanto limitada na presença de agregado carbonático e/ou argila. Os estudos de caso apresentaram composições de envolvendo cal, areia, saibro, cimento e agregado carbonático. Fragmentos de conchas/corais foram encontrados em diversas amostras. As patologias foram relacionadas a torrões de argila na composição da argamassa, falta de aglomerante e incompatibilidade entre emboço e reboco. A apresentação de resultados na forma de mapas temáticos foi eficaz no ambiente multidisciplinar. A aplicação da metodologia se demonstrou viável e útil no apoio às decisões de restauro de argamassas de fachadas históricas, podendo ser aplicada também a argamassas contemporâneas.
Façade renders protect the building, its content and reveal its identity. Those roles are even more important on cultural heritage buildings. Renders decay under weathering, damp, vandalism, unsuccessful interventions and manufacturing defects. This thesis presents and applies an assessment methodology concerning historical façades plasters, construction methods and damage. The architectural preservation literature is reviewed, highlighting the importance of such assessment. Rendering decay mechanisms are compiled, focused on historical mortars. Practical field information is described, including façade vertical access, assessment objectives definition, historical evolution representation, field forms design and implied costs. An inspector formation proposal is outlined. Materials, construction methods and damage assessment literature are reviewed and a method is proposed. Damage assessment relies on visual inspection and nondestructive essay, using ABS faced hammer percussion. Sampling criteria and laboratory protocols are reviewed and proposed. The proposed protocol applies macroscopic analysis, X-ray diffraction (XRD), petrography and acid digestion chemical analysis. Suggestions are made concerning results synthesis and presentation to preservation team. Presented methodology, based on simplicity and low cost, was developed during three case studies: two on São Cristóvão Palace Main Court and Main Façade- and the exterior façades of the future Casa da Moeda do Brasil Museum, both in Rio de Janeiro. The three studies account for roughly 4.400 m² of assessed rendered surface. Construction methods and materials assessment contributed to the buildings historical studies and pathology comprehension. Percussion assessment evaluated damage on 69% of the Main Court rendered area, although visual inspection accounted only 5% of missing render. Careful demolition of damaged render proved a 4% deviation from percussion assessment forecast. Laboratory protocol grouped samples based on macroscopic evaluation and/or XRD. Only group representatives were submitted to further analysis. XDR was used for mineralogical identification. Petrography proved a very versatile essay, yielding data on composition, granulometry, porosimetry, approximated formulation and geological history. Plaster composition was evaluated by chemical analysis blind proofed for sand, lime and/or Portland cement, though impaired when carbonate aggregate and clay particles are present. Case studies showed various mortar formulations, comprising lime, sand, clay, cement and carbonate aggregate. Sea shell/reef fragments were found in several samples. Pathology was related to the presence of clay lumps, lack of binder and incompatibility between plaster layers. Thematic maps were successfully used in results presentation to multidisciplinary teams. The proposed methodology is viable and useful, supporting decisions within architectural preservation of historical façades plaster rendering. Contemporary façades can benefit from the methodology as well.

Ce projet porte sur l'étude de l'altération du smalt, un pigment de synthèse constitué de verre bleu teinté au Co et riche en K. Utilisé du XVe au XVIIIe siècle dans les peintures de chevalet, fresques et sculptures polychromes, le smalt est connu pour sa tendance à perdre sa couleur bleue et à virer au jaune-gris en présence de liant. Cette décoloration irréversible, bien que connue des artistes de l'époque, entraîne des modifications permanentes des œuvres. Si le mécanisme d'altération du smalt a été étudié et est globalement compris, les facteurs influençant ce phénomène, tels que la lumière, l'humidité, la température, le liant et la présence d'autres pigments, demeurent mal identifiés. Or, dans une perspective de conservation des œuvres, il est crucial de mieux comprendre ces facteurs. Par ailleurs, la restitution de l'état initial des peintures reste une question centrale pour les conservateurs et restaurateurs.Le premier objectif de cette thèse est de définir les paramètres influençant la dégradation du smalt dans les peintures de chevalet et sur des échantillons modèles. L'interaction du smalt avec le blanc de plomb, pigment blanc largement utilisé à l'époque, a été étudiée. Le blanc de plomb existe sous deux formes cristallines, la cérusite et l'hydrocérusite, en équilibre acido-basique. L'analyse d'échantillons modèles par microscopie électronique à balayage couplée à la spectroscopie dispersive en énergie (MEB-EDX), la spectroscopie XANES et la diffraction des rayons X (DRX) a révélé que la présence de blanc de plomb accélère l'altération du smalt, et de façon plus prononcé lorsqu'il est sous forme d'hydrocérusite que de cérusite. Les diffractogrammes ont aussi montré une transformation partielle du blanc de plomb après vieillissement.Le liant étant une source de protons dans le mécanisme d'altération du smalt, son influence a été examinée en recréant et en vieillissant des échantillons modèles avec différents liants : huile de lin, huile de noix et jaune d'œuf. Ces échantillons ont été analysés pour comprendre les effets du vieillissement sur leur composition. Parallèlement, des coupes transversales de peintures historiques contenant du smalt ont été examinées selon les mêmes méthodes pour valider les résultats obtenus sur les échantillons modèles. Les analyses MEB-EDX ont permis de suivre la composition des grains de smalt, aussi bien dans les échantillons modèles que dans les peintures historiques. Par la suite, la spectroscopie XANES aux seuil K du Co et du K a permis de déterminer l'état de coordination des ions Co2+ dans les grains de smalt et d'évaluer leur altération. Le XANES au seuil K du K a également permis d'analyser les transformations subies par le K lors de sa lixiviation, offrant ainsi des indices sur la modification de la matrice silicatée et son interaction avec le liant au cours de l'altération.Le second objectif de cette thèse est de proposer une première procédure pour simuler numériquement la couleur d'origine des œuvres contenant du smalt altéré. Bien que la restauration physique de la couleur du pigment soit impossible, des simulations virtuelles peuvent permettre de recréer l'apparence initiale des peintures. Une méthode combinant la cartographie par fluorescence macroscopique de rayons X (MA-XRF), la spectroscopie d'imagerie par réflectance (RIS), la spectroscopie d'absorption X (XAS) et le Machine Learning pour simuler les couleurs originales des tableaux en prenant en compte leurs matérialitées a été développée. La MA-XRF permet de révéler la répartition des éléments, la RIS a capturé les données spectrales, et la XAS a fourni des informations sur la coordination du Co. L'apprentissage automatique a permis de prédire avec précision les teintes d'origine. Cette méthode, constitue une avancée majeure pour la visualisation des œuvres touchées par la dégradation du smalt, apportant ainsi une aide précieuse aux conservateurs et historiens de l'art
This PhD focuses on the study of the degradation of smalt, a synthetic pigment made of Co-tinted glass rich in K. Used from the 15th to the 18th centuries in easel paintings, frescoes, and polychrome sculptures, smalt is known for its tendency to lose its blue color and turn yellow-gray in the paint layers. This irreversible discoloration, though known to artists of the time, leads to permanent modifications in the artworks' appearances. While the degradation mechanism of smalt has been studied and is generally understood, the factors influencing this complex process, such as light, humidity, temperature, binder, and the presence of other pigments, remain poorly identified. In the context of conserving works containing smalt, understanding these factors is crucial. Additionally, restoring the original state of the paintings remains a central concern for conservators and restorers.The first objective of this thesis is to define the parameters influencing the degradation of smalt in easel paintings and on model samples. The interaction of smalt with lead white, a widely used white pigment at the time, has been studied. Lead white exists in two crystalline forms, cerussite, and hydrocerussite, in an acid-base equilibrium. The analysis of model samples using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray absorption near edge spectroscopy (XANES), and X-ray diffraction (XRD) revealed that the presence of lead white, especially in the form of hydrocerussite, accelerates smalt degradation. The diffractograms also showed partial transformation of lead white in aged samples.Since the binder is a source of protons in the smalt degradation process, its influence was examined by creating and aging model samples with different binders: linseed oil, walnut oil, and egg yolk. These samples were analyzed to understand the effects of aging on their composition. In parallel, cross-sections of historical oil paintings containing smalt were examined using the same methods to validate the results obtained on the model samples. SEM-EDX analysis tracked the composition of smalt grains, both in model samples and historical paintings. Subsequently, XANES spectroscopy at the Co and K K-edges was used to determine the coordination state of Co ions in smalt grains and assess their degradation. XANES at the K K-edge also helped analyze the transformations K undergoes during leaching, providing insights into the alteration of the silicate matrix and its interaction with the binder during the degradation process.The second objective of this thesis is to propose a procedure to digitally simulate the original color of artworks containing degraded smalt. Although physical restoration is impossible, virtual simulations can recreate the initial appearance of the paintings. A method combining macro X-ray fluorescence mapping (MA-XRF), reflectance imaging spectroscopy (RIS), X-ray absorption spectroscopy (XAS), and Machine Learning has been developed to reconstruct the original colors of the paintings, taking into account the materiality of the artworks. MA-XRF reveals the distribution of elements, RIS captures spectral data, and XAS provides information about Co coordination. Machine learning accurately predicts the original hues. This method represents a significant breakthrough in visualizing artworks affected by smalt degradation, offering valuable support to conservators and art historians