Made available in DSpace on 2014-06-12T18:07:26Z (GMT). No. of bitstreams: 2 arquivo7890_1.pdf: 4449935 bytes, checksum: 6ac8b6b694f8f7afba637c3737735944 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2004 / Os supercondutores de alta temperatura crítica (High Temperature Superconductors - HTSC) a base de óxido de cobre têm sido amplamente estudados através do efeito de substituição e/ou dopagem. Estes estudos têm mostrado ser de grande importância para a compreensão do fenômeno da supercondutividade nesses compostos. A supercondutividade nesses compostos é localizada nas camadas bidimensionais de CuO2. A dopagem com óxidos de metais da série 3-d revela que é possível obter um aumento da corrente crítica mesmo quando se tem um decréscimo na temperatura de crítica (Tc). Neste trabalho, estudamos o efeito da substituição do CuO por MS (M = Zn e Ni) no composto Ca0,5LaBa1,5Cu3O7−δ (CLBCO). As amostras foram preparadas por reação do estado sólido usando-se óxidos e sulfetos metálicos com alto grau de pureza. As amostras foram caracterizadas estruturalmente por difração de raiosx (DRX) com análise de Rietveld, microestruturalmente por microscopia eletrônica de varredura (MEV) e por estudo de dispersão de energia de raios-x (EDX). Foram estudadas também as propriedades supercondutoras por medidas de susceptibilidade ac, magnetização dc e de resistividade elétrica. A análise de DRX indica que todas as amostras apresentam estrutura tetragonal, com simetria de grupo espacial P4/mmm, independente da concentração do dopante. A MEV revela que os grãos possuem morfologia aproximadamente retangular e que o tamanho diminui com o aumento da dopagem. O EDX revela a presença de impurezas, em pequena concentração, e que o ZnS e o NiS são incorporados no composto. As medidas das propriedades supercondutoras mostraram que há um grande decréscimo de Tc quando comparado ao mesmo sistema dopado com óxidos dos elementos (Zn e Ni). No capítulo 1, é feita uma descrição da evolução histórica dos principais fatos ocorridos no desenvolvimento da supercondutividade desde sua descoberta até os dias atuais. No capítulo 2, fazemos uma evolução histórica das principais teorias usadas para descrever o estado supercondutor desde sua descoberta, com exceção da teoria BCS. No capítulo 3, descrevemos a formação da estrutura cristalina dos supercondutores a base de cobre juntamente com as suas principais propriedades físicas. Enfatizamos a formação da estrutura dos compostos conhecidos como YBCO e do composto CLBCO, e detalhamos as principais propriedades do efeito de dopagem observado no composto CLBCO. No capítulo 4, descrevemos detalhadamente as técnicas experimentais usadas no desenvolvimento deste trabalho. No capítulo 5, descrevemos o processo de preparação das amostras bem como o uso das técnicas para caracterização das propriedades estruturais, microestruturais e supercondutoras. Apresentamos e discutimos os principais resultados obtidos. No capítulo 6, apresentamos as conclusões do nosso trabalho

Dans cette thèse, on a travaillé sur 3 plantes médicinales : Ammoides pusilla, Pituranthos tortuosus et Tetraclinis articulata. L'objectif était : (i) d'identifier la composition chimique des extraits organiques et des huiles essentielles issues de ces plantes, (ii) établir un screening biologiques in vitro des activité anti-Alzheimer, anti-Superoxyde dismutase, anti-xanthine oxidase, antidiabétique, anti-inflammatoire et anti-cancer (iii) évaluer in vivo le pouvoir hépatoprotecteur et anti-inflammatoire de A. pusilla, (iv) étudier l'activité litholytique de l'extrait aqueux d'A. pusilla contre différents types de calculs rénaux et (v) déterminer la relation structure-activités de 20 flavonoïdes. Les extraits organiques ont été obtenus par extraction avec des solvants de polarité croissante. D'autre part, une hydrodistillation a permis d'extraire les huiles essentielles de chaque partie aérienne. Une caractérisation de la composition chimique de ces extraits/huiles essentielles a été établie par CPG-SM/CG-FID et HPLC (pour les extraits). L'activité anti-cancer a été réalisée par le test MTT sur des lignées cellulaires différentes. Pour A. pusilla, 2 nouveaux composés ont été identifiés dans l'extrait de cyclohexane et 4 nouveaux composés dans l'extrait de dichlorométhane. L'effet hépato protecteur de l'extrait d'A. pusilla sur le foie a été mis en évidence. L'extrait de dichlorométhane a permis d'obtenir 77,02% d'inhibition, pour l'activité anti-inflammatoire in vivo. Pour P. tortuosus, 17 composés ont été détectés dans l'huile essentielle pour la première fois. Pour les 20 flavonoïdes testés le pouvoir antioxydant a été corrélé à des propriétés biologiques. Cinq types de calculs rénaux différents ont été identifiés (typologie et composition élémentaire) par MEB/EDX. A. pusilla a présenté une activité litholytique à 100% pour les calculs rénaux de type urinaire et oxalate de calcium. / In this thesis, we worked on 3 medicinal plants: Ammoides pusilla, Pituranthos tortuosus and Tetraclinis articulata. The aim was: (i) identify the chemical composition of organic extracts and essential oils from these plants, (ii) establish a biological screening of in vitro anti-Alzheimer, anti-superoxide dismutase, anti-xanthine oxidase , anti-diabetic, anti-inflammatory and anti-cancer activities (iii) evaluate in vivo hepatoprotective and anti-inflammatory power of A. pusilla, (iv) study litholytic activity of aqueous extract of A. pusilla against different types of kidney stones and (v) determine the relationship structure-activity of 20 flavonoids. The organic extracts were obtained by extraction with solvents of increasing polarity. Furthermore, a hydrodistillation was used to extract essential oils from each aerial part. A characterization of the chemical composition of these extracts / essential oils was determined by GC-MS/GC-FID and HPLC (for extracts). The anti-cancer activity was carried out by MTT assay on different cell lines. For A. pusilla, two novel compounds were identified in the extract of cyclohexane and 4 novel compounds in the dichloromethane extract. A. pusilla hepatoprotective effect on the liver has been highlighted. The dichloromethane extract of P. tortuosus gives 77.02% inhibition for in vivo anti-inflammatory activity, 17 compounds were detected in the essential oil for the first time. For the 20 flavonoids tested the antioxidant power was correlated with biological properties. Five different types of kidney stones have been identified (typology and elemental composition) using SEM / EDX. A. pusilla litholytic activity presented at 100% for urinary-type and calcium oxalate kidney stones.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17518号 / 工博第3677号 / 新制||工||1559(附属図書館) / 30284 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 河合 潤, 教授 酒井 明, 教授 邑瀬 邦明 / 学位規則第4条第1項該当

The object of the present investigation has been to relate the mechanical properties of a high strength Mg-Y-Gd alloy to alloy composition, extrusion parameters and microstructure. Three alloys with various Y: Gd ratios, of similar total solute content (at %) to Elektron 675, have been investigated in this study:9122: Mg – 6.5 wt % Y – 7.6 wt % Gd – 0.4 wt % Zr 9123: Mg – 8.2 wt % Y – 4.8 wt % Gd – 0.4 wt % Zr9124: Mg – 2.6 wt % Y – 13.1 wt % Gd – 0.4 wt % ZrThe three alloys were extruded at 425 and 475 °C with extrusion ratio 17: 1 to give two samples from each alloy, group a and b. Alloy 9122 was also extruded at 460 and 500 °C with extrusion ratio 10: 1 to give another two samples c and d. The as-cast microstructure of the three alloys comprised equiaxed α-magnesium grains and regions of eutectic decorating some grain boundaries formed during solidification of the ingot. Variation of extrusion parameters has resulted in a dispersion of different volume fractions of second phase particles in different groups of samples. The chemistry of second phase particles was determined by in-situ bulk energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD); magnesium yttrium was identified for near-equiaxed particles and yttrium hydride was proposed as a possible identification for cuboids. The composition of these compounds varied with variation of Y: Gd in the three alloys. Variation of extrusion ratio and extrusion temperature had a clear effect on the evolution of the extruded microstructure and the development of crystallographic texture as characterized by optical microscopy, electron backscattered diffraction (EBSD) and inverse pole figures. The microstructure of the extruded samples was refined during extrusion through dynamic recrystallization (DRX). Samples of groups a, b and c exhibited a microstructure in which bands of fine, equiaxed grains in association with stringers of second phase particles (running along the extrusion direction) were formed between bands of coarse, equiaxed grains. Sample d contained only small volume fraction of second phase particles; only a few alternating bands were formed and considerable grain growth occurred. A random texture was developed during extrusion in samples of groups a, b and c; a wide spread of orientations accompanied by a (new) previously unreported texture component in which basal poles of some grains are aligned nearly parallel to the extrusion direction was developed. The new texture component was weak in sample c and entirely suppressed in sample d. The asymmetry in tensile and compressive yield stress commonly associated with magnesium extrusions was nearly eliminated in samples of group a and b. The new basal texture component was likely to be a result of nucleation of DRX on sites rotating into this orientation. This is proposed to be a result of deformation in those regions in grains was accomodated by basal, prismatic and pyramidal slip. The grains nucleated in this orientation appear to have developed a form of preferred growth which led to strengthening of this new component following solution treatment. The effect of varying solute content (Y & Gd) and different ageing temperatures 150, 200, 250 and 300 °C (T5 & T6) on the ageing response and precipitation reaction were investigated using hardness measurements and transmission electron microscopy (TEM). Alloy 9122 showed the highest ageing response of the three alloys at 150, 200 and 250 °C (T5 & T6); specimens aged in the T5 gave higher hardness than the T6 treatment, a contribution of fine grain size. The three alloys did not respond to ageing at 300 °C. The precipitation reactions that occurred in alloy 9122 (at under, peak and overageing) and alloys 9123 and 9124 (at peak ageing) at 250 °C have been characterized. The precipitation sequence observed in sample 9122a can be described as: . The microstructure of peak aged specimens of alloys 9122 and 9124 were similar; both contained a homogeneous dispersion of precipitates and some metastable precipitates. Alloy 9123 contained only a homogeneous dispersion of precipitates and remnants of precipitates and no precipitates. The enhanced thermal stability of and phases are most likely responsible for the superior elevated temperature properties of Elektron 675. The effect of varying solute content (Y & Gd) and extrusion parameters on the mechanical properties were determined using tensile testing. Alloys 9122 and 9124 exhibited higher 0.2 % proof stress and UTS than alloy 9123 and alloy 9122 was the hardest alloy. Alloy 9122 exhibited the worst ductiliy (T5 and T6) among 9123 and 9124, and this was attributed to the higher volume fraction of second phase particles. The ductility of samples a, b and c in the as-extruded & T5 conditions, particularly in the transverse direction, was limited by stringers of second phase particles, whereas ductility and failure in sample d was governed by grain size and texture. The ductility and failure of all samples aged in the T6 treatment, irrespective of the extrusion history, was controlled by texture and grain size rather than stringers of second phase particles.

[EN] An integrated methodology incorporating preliminary archaeometric studies, design and performance of conservative and preventive treatments, as well as the design of an expositive support for a Montefortino helmet conserved at the Museum of Requena (Valencia, Spain), is presented. It was a bronze helmet dated back at the 3rd century B.C., providing from a terrestrial archaeological context showing intense degradation caused by cyclic corrosion associated to cuprous chlorides known as "bronze disease". The object showed advanced intergranular corrosion with deep attack of nantokite and minerals of the atacamite family, giving rise to an important structural fragility. The singularity of the object either in regard to its historic and documental value as well as in regard to its problems of mechanical and physico-chemical deterioration, have been faced from an interdisciplinary perspective around three specific aspects: i) the archaeometric study, focused on the characterization of the mechanical and physico-chemical deterioration using radiographic and analytic techniques, mainly, Optical Microscopy (OM), Scanning Electron Microscopy (SEM/EDX), X-ray Fluorescence Spectrometry (XRF) and Volammetry of Microparticles (VMP); ii) structural study on the mechanical resistance of the helmet using digital modeling techniques; iii) application of chemical decloruration conservative treatments accompanied by the study of expositive systems, including the design of a specific support. The monitoring of the conservation state of the object was carried out by means of climatic control and analytical examination after seven years of Museum exposition, showing that the helmet still maintains an acceptable level of mechanical and physico-chemical stability. / [ES] Se desarrolla una metodología integrada que atiende a los estudios arqueométricos previos, el diseño y ejecución de tratamientos conservativos y preventivos, así como el diseño del soporte expositivo de un Casco Montefortino conservado en el Museo de Requena (Valencia). Se trata de un casco de bronce de en torno a la mitad del siglo III a.C., procedente de un contexto arqueológico terrestre y que presentaba un proceso de degradación avanzado a causa de la corrosión cíclica producida por los cloruros cuprosos conocida como "enfermedad del bronce", habiéndose detectado una corrosión intergranular avanzada con ataques profundos de nantokita y minerales del grupo de la atacamita dando lugar, como consecuencia, a una fragilidad estructural importante. Tanto la singularidad de la pieza en cuanto a su valor histórico y documental, como el interés derivado de sus problemas de deterioro mecánico y químico, se han abordado desde una perspectiva interdisciplinar en torno a tres ámbitos específicos: i) el estudio arqueométrico, centrado en la caracterización de los deterioros físico-químicos y estructurales mediante técnicas radiográficas y analíticas, incorporando Microscopía Óptica (MO), Microscopía Electrónica de Barrido (SEM/EDX), Espectrometría por Fluorescencia de rayos X y Voltamperometría de Micropartículas (VMP); ii) el estudio estructural mediante técnicas de modelización digital sobre la resistencia mecánica del casco; iii) la aplicación de tratamientos conservativos de decloruración química acompañados del estudio de sistemas expositivos incluyendo el diseño de un soporte específico. Se ha procedido igualmente a un seguimiento de la pieza en exposición mediante control climático y examen analítico tras siete años de exposición, evidenciando que el Casco continúa manteniendo unos niveles de estabilidad físico-químicos y estructurales aceptables / [CAT] Es presenta una metodologia integrada atenent als estudis arqueomètrics previs, el disseny i realització de tractaments conservatius i preventius així com el disseny d'un suport expositiu d'un Casc Montefortí conservat al Museu de Requena (València). Es tracta d'un casc de bronze datat al voltant de la meitat del segle III a.C., provinent d'un context arqueològic terrestre i que mostrava un procés de degradació avançat a causa de la corrosió cíclica produïda pels clorurs cuprosos coneguda com "malaltia del bronze", havent-se detectat una corrosió inter-granular avançada amb atacs profunds de nantokita i minerals del grup de l'atacamita donant lloc, com a conseqüència, a una fragilitat estructural important. Tant la singularitat de la peça en quant al seu valor històric i documental, com l'interès derivat dels seus problemes de deteriorament mecànic i químic, se han abordat des d'una perspectiva inter-disciplinar al voltant de tres àmbits específics: i) l'estudi arqueomètric, centrat en la caracterització dels deterioraments físic-químics i estructurals mitjançant tècniques radiogràfiques i analítiques, tot i incorporant Microscòpia Òptica (MO), Microscòpia Electrònica de Escombrat (SEM/EDX), Espectrometria per Fluorescència de raigs X i Voltamperometria de Micropartícules (VMP); ii) l'estudi estructural mitjançant tècniques de modelització digital sobre la resistència mecànica del casc; iii) l'aplicació de tractaments conservatius de de-cloruració química acompanyats de l'estudi de sistemes expositius incloent el disseny d'un suport específic. S'ha procedit igualment a un seguiment de la peça en exposició mitjançant control climàtic i examen analític rere set anys de exposició, evidenciant que el Casc continua mantenint uns nivells d'estabilitat fisico-química i estructural acceptables. / Martínez Lazaro, ID. (2016). Estudios integrados de procesos analíticos y conservativos de bronce arqueológico. Aplicación a un casco montefortino y otros materiales afines [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61456 / TESIS

The application of low-pressure low-temperature hydrogen plasma on artificial corrosion layers on bronze has been studied. For this purpose, three sets of bronze corroded samples were prepared. The first step of the model sample preparation was grinding of the bronze surface by using emery with 60, then 280 and finally by 600 grains density, in order to achieve the defined surface roughness. The next step of the work were optical and scanning electron microscopy observations with energy dispersive X-ray micro analysis (SEM-EDX) of the prepared bronze sample for purpose of surface structure characterization and element composition determination. Bronze samples with defined surface structure were corroded in different corrosion atmospheres. Three different model corrosion layers were formed by acidic atmospheres of hydrochloric acid, nitric acid and sulphuric acid. The element composition and structure of corrosion layer was determined by SEM-EDX again. The different amounts of oxygen, nitrogen, chlorine, sulfur, copper, tin and lead in the corrosion layer according to different types of corrosion atmospheres were determined. The next and also main part of the work was a plasma chemical reduction of corroded samples. The plasma reactor used the RF discharge (13.56 MHz) created in quartz tube with outer electrodes. The generation of capacitively coupled plasma in continuous or pulse mode by different supplied power was carried out. The plasma radiation emitted from the RF discharge during the sample treatment was measured by optical emission spectroscopy. The quantity of OH radical created in an active discharge by reactions of atomic hydrogen with the corrosion layer is a significant indicator of a reduction process. Therefore the OH radical band integral intensities observed as a function of the treatment time were used as a monitor for plasma chemical reduction process. The OH emission showed different behavior depending on corrosion layer composition during the plasma treatment. The transformations of the corrosion layer due to the plasma effect were investigated by means of SEM-EDX once again. Changes in the element composition of corrosion (or surface) layers in consequence of plasma chemical treatment are given. Generally, the element composition after the plasma chemical treatment showed explicitly that oxygen and chlorine content in the corrosion layer decreased, nitrogen was removed totally. Metal deposition on the reactor wall was observed occasionally. The SEM-EDX analyzes also showed that in some cases the tin content in sample surface layers was significantly decreased. For that reason, in case of bronze sample (artifacts) treatment, the sample and plasma temperature seem to be very important parameters for the process optimization. The acceptable conditions for plasma chemical treatment has been found in case of corrosion layer formed by nitric acid, only. The other corrosions will be a subject of further studies.

Das Wasser der Elbe auf der Höhe von Dresden enthält anorganische Kolloidpartikel, deren Partikelgrößenverteilung nahezu den gesamten kolloidalen Definitionsbereich (1 nm bis 1 µm) überstreicht und die vor allem aus sekundär ausgeschiedener amorpher Kieselsäure sowie aus Oxyhydroxiden des Fe, Al und Mn bestehen. Als wichtigstes Schwermetall führen sie Zn. Ihre Konzentration liegt unter 5×10-1 mg/l, um etwa Faktor 30 unter der Konzentration der Schwebstoffe des Elbwassers (Partikel >1 µm). Wegen ihrer hohen spezifischen Oberfläche sind die Kolloidpartikel als potentielle Träger für Schadstoffe trotz dieser geringeren Massekonzentration nicht gegenüber den Schwebstoffen zu vernachlässigen. Die in der Elbe gemessene Partikelgrößenverteilung ähnelt derjenigen, die zu einem früheren Zeitpunkt im Rhein gefunden worden war. Auch die chemische Zusammensetzung der Kolloidpartikel in der Elbe ist der der Partikel des Rheins ähnlich. Die Konzentration der Kolloidpartikel in der Elbe war aber um Faktor 5 bis 10 höher als im Rhein. Grund für letzteres ist wahrscheinlich der höhere Gehalt des Elbwassers an gelöstem Kohlenstoff (DOC). Im "Bulk" eines Flusses sind kolloidgetragene Schadstoffe - anders als schwebstoffgetragene - vermutlich fast genauso mobil wie echt gelöste. Unterschiede zwischen den Transportgeschwindigkeiten der kolloidgetragenen und der echt gelösten Spurenstoffe treten in bestimmten Situationen auf, in denen das Wasser den "Bulk" eines Flusses verlässt (Sickerbereich unter dem Fluss, Ästuar). Es werden Schlussfolgerungen über die Rolle von Kolloidpartikeln im Ökosystem eines Flusses gezogen und noch bestehende Forschungsdesiderate benannt.

[ES] Las piezas numismáticas constituyen un importante porcentaje de las colecciones de los museos y una de las evidencias que con mayor frecuencia se encuentra en las excavaciones, tratándose de vestigios arqueológicos e históricos fundamentales para el estudio de diferentes aspectos de las sociedades pasadas. Para la investigación y la caracterización de estos materiales es necesario el empleo de técnicas analíticas no invasivas o nanoinvasivas que no comprometan la integridad de las monedas. En este trabajo se presentan los resultados obtenidos en la exploración de las capacidades de dos técnicas instrumentales analíticas, VIMP y FIB-FESEM-EDX, ambas de carácter nanoinvasivo, en colecciones numismáticas fabricadas en aleaciones en base cobre, escasamente empleadas en el estudio de patrimonio metálico hasta la fecha. Además, y en cada caso de estudio abordado, se han diseñado estrategias multitécnica que incluye el uso de SEM-EDX, espectroscopia FTIR, M.O., colorimetría y espectroscopia Raman. En una primera parte de la investigación se han desarrollado metodologías analíticas para la identificación y discriminación de aleaciones, productos de corrosión e intervenciones previas en tres colecciones de distinta titularidad y procedentes de diferentes ambientes. La primera colección, procede de un ambiente aéreo o atmosférico y es de titularidad privada, la colección Doménech-Francés. La segunda colección, procede de un ambiente de enterramiento y pertenece al Museu de Prehistòria de València. La última colección estudiada con esta finalidad procede de un ambiente subacuático, y pertenece al Museo Nacional de Arqueología Subacuática. En la segunda parte, el trabajo se centra en el desarrollo de una metodología innovadora basada en la técnica de electroquímica en estado sólido VIMP, que permite la discriminación entre cecas y el conocimiento de las técnicas de acuñación empleadas. Esta nueva metodología se ha implementado sobre dos casos de estudio diferentes: el primero consiste en una serie de maravedís acuñados entre 1661 y 1664 por Felipe IV, y el segundo, en una colección de monedas íberas acuñadas en las cecas de Cástulo, Obulco e Iltirta entre los siglos II y I a.C., pertenecientes al Museu de Prehistòria de València. / [CA] Las peces numismàtiques constitueixen un important percentatge de les col·leccions dels museus i una de les evidències que amb major freqüència es troba en les excavacions, i es tracta de vestigis arqueològics i històrics fonamentals per a l'estudi de diferents aspectes de les societats passades. Per a la investigació i la caracterització d'aquests materials és necessari l'ús de tècniques analítiques no invasives o nanoinvasives, que no comprometen la integritat de les monedes. En aquest treball es presenten els resultats obtinguts en l'exploració de les capacitats de dues tècniques instrumentals analítiques, VIMP i FIB-FESEM-EDX, ambdues de caràcter nanoinvasiu, en col·leccions numismàtiques fabricades en aliatges amb base de coure, escassament emprades en l'estudi del patrimoni metàl·lic fins avui. A més, en cada cas d'estudi abordat, s'han dissenyat estratègies multitècnica que inclouen l'ús de SEM-EDX, espectroscòpia FTIR, M.O., colorimetria i espectroscòpia Raman. En una primera part de la investigació s'han desenvolupat metodologies analítiques per a la identificació i discriminació d'aliatges, productes de corrosió i intervencions prèvies en tres col·leccions de diferent titularitat i procedents de diferents ambients. La primera col·lecció, procedeix d'un ambient aeri o atmosfèric i és de titularitat privada, la col·lecció Doménech-Francés. La segona col·lecció procedeix d'un ambient d'enterrament i pertany al Museu de Prehistòria de València. La última col·lecció estudiada amb aquesta finalitat procedeix d'un ambient subaqüàtic i pertany al Museu Nacional d'Arqueologia Subaqüàtica. En la segona part, el treball se centra en el desenvolupament d'una metodologia innovadora basada en la tècnica d'electroquímica en estat sòlid VIMP, que permet la discriminació entre seques i el coneixement de les tècniques d'encunyació emprades. Aquesta nova metodologia s'ha implementat sobre dos casos d'estudi diferents: el primer consisteix en una sèrie de maravedís encunyats entre el 1661 i el 1664 per Felip IV; i el segon, en una col·lecció de monedes iberes encunyades a les seques de Cástulo, Obulco i Iltirta entre els segles II i I a. de C., pertanyents al Museu de Prehistòria de València. / [EN] The numismatic pieces constitute an important part of the collections of the museums and one of the evidences that more frequently found in the excavations, being archaeological and historical vestiges fundamental for the study of severe aspects of the past societies. The use of non-invasive or nanoinvasive analytical techniques that do not compromise the integrity of the coins is essential for the investigation and characterization of these materials. This PhD presents the results obtained in the exploration of the capabilities of two nanoinvasive analytical instrumental techniques, VIMP and FIB-FESEM-EDX, in numismatic collections made of copper-based alloys, scarcely used in the study of heritage metallic so far. In addition, and in each study case discussed, multi-technical strategies have been designed that include the use of SEM-EDX, FTIR spectroscopy, O.M., colorimetry and Raman spectroscopy. In the first part of the investigation, analytical methodologies for the identification and discrimination of alloys, corrosion products and previous interventions in three collections of different ownership and coming from different environments have been developed. The first collection, comes from an air or atmospheric environment, is privately owned, the Doménech-Francés collection, the second collection, comes from a burial environment and belongs to the Museum of Prehistory of Valencia, and the last collection studied for this purpose, comes from an underwater environment and belongs to the National Museum of Underwater Archaeology. In the second part, the work focuses on the development of an innovate methodology based on the technique of solid-state electrochemistry VIMP that allows the discrimination between mints and the knowledge of the coinage techniques used. This new methodology has been implemented on two different case studies: the first consists of a series of maravedís coined between 1661 and 1664 by Philip IV, and the second, in a collection of iberian coins minted in the mints of Cástulo, Obulco and Iltirta between the 2nd and 1st centuries BC, and belonging to the Museum of Prehistory of Valencia. / Agradecer todo el apoyo institucional que he tenido: al contrato FPI del Ministerio de Economía, Industria y Competitividad del que he podido disfrutar durante estos cuatro años (referencia de la ayuda BES-2015-072439) enmarcado dentro de los proyectos CTQ2014-53736- C3-1-P y CTQ2014-53736-C3-2-P, al proyecto CTQ2017-85317-C2-1-P, del Ministerio de Ciencia, Innovación y Universidades y cofinanciado por el Fondo Europeo de Desarrollo Regional (ERDF) y la Agencia Estatal de Investigación (AEI) / Álvarez Romero, C. (2020). DESARROLLO DE MÉTODOS DE CARACTERIZACIÓN Y CONTROL DE TRATAMIENTOS DE CONSERVACIÓN DE COLECCIONES NUMISMÁTICAS MEDIANTE TÉCNICAS DE MICROSCOPÍA ELECTRÓNICA Y NANOELECTROQUÍMICA [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/140316 / TESIS

L'objectif de cette étude est d'étudier le potentiel d'Opuntia ficus-indica (Ofi) en tant que biomoniteur dans un environnement contaminé par des dépôts atmosphériques enrichis en métaux lourds. Trois sites d'étude pollués ont été sélectionnés: industriel, minier et routier. Le phénomène de bioaccumulation a été validé en analysant la concentration en métaux lourds par SAA et ICP-MS dans plusieurs raquettes d'âge différent, dans les fruits et les racines. L'identification de l'origine du Pb a été étudiée à partir de la signature isotopique du Pb (TIMS) dans les raquettes, les racines et les sols, avec une caractérisation microscopique (MEB-EDX) des particules déposées à la surface des raquettes. Le taux de bioaccumulation du Pb suite à une exposition racinaire ou foliaire à des particules de fluorapatite synthétisées et enrichies en Pb à permis de préciser les voies de transfert vers la plante. Ainsi, la distribution particulaire ou dispersée du Pb dans les raquettes contaminées a été identifiée au moyen de cartographies MEB-EDX et µXRF. Les résultats obtenus montrent qu'Ofi est un bioaccumulateur du Pb, Cd et Cr. Les signatures isotopiques dans les raquettes révèlent la nature des diverses sources polluantes tout en donnant une indication sur l'évolution de la pollution atmosphérique au cours du temps. Le taux le plus élevé de Pb a été mesuré dans les raquettes contaminées à leur surface par de la fluorapatite. Les analyses microscopiques ont démontré pour les deux approches suivies l'intégration des particules déposées à la surface des raquettes au niveau de la cuticule, des trichomes et des stomates. Cette obsevation est cohérente avec la cartographie obtenue en µXRF. Notre étude démontre le potentiel de cette plante cosmopolite qu'est Ofi en tant que biomoniteur. / This study reports the potential of Opuntia ficus-indica (Ofi) as a biomonitor of atmospheric pollution in three heavily polluted sites, i.e., industrial, mining and road sites. The bioaccumulation phenomenon by Ofi was investigated by studying the heavy metal concentrations in different cladodes of various ages, roots and fruits, using AAS and ICP-MS. To identify the origin of Pb in cladodes, two types of methods were used: TIMS analysis which provided the lead isotopes ratios in cladodes, roots and soil samples, and SEM-EDX analysis at the cladode surface which provided the elemental distribution of Pb and airborne particles and a characterization of their chemical structure at the microscopic scale. A second study was also carried out by testing Pb bioaccumulation after foliar and roots exposure to synthesized fluorapatite particles enriched with Pb. SEM-EDS and µXRF analyses were used to follow the Pb concentration from the contaminated surface to the internal tissues. The results show that Ofi is indeed a bioaccumulator of Pb, Cd and Cr. The Pb isotopic signatures indicate that Ofi is a sensitive species to local aerial pollution and their successive cladodes obviously identify the evolution of air pollution with time. In addition, Ofi cladodes were found more contaminated with lead after direct foliar contamination. SEM-EDS measurements underlined in the two studies the retention of deposited particles on specific zones of the cladode surface (cuticle, trichome and stomata), which were also identified by µXRF cartography. These results represent the first demonstration of the potential of using Ofi, a cosmopolitan plant, as a biomonitor.

The purpose of this study was to evaluate the effects of sodium hypochlorite on the organic and inorganic composition of enamel. Background: With the advent of enamel bonding for orthodontic appliances in the late 1970s, it has been shown that traditional phosphoric acid etching affects the inorganic portion of the enamel.1, 2 In an attempt to enhance the acid etching pattern and, furthermore, the bond strength, additional pretreatment techniques that target the organic components of the enamel biofilm have been proposed. One such method is the non-invasive enamel pretreatment with 5.25% sodium hypochlorite (NaOCl) prior to phosphoric acid etching.3, 4 It has been suggested that the mechanism by which sodium hypochlorite enhances the etching pattern is enamel deproteinization, in which organic elements, including the acquired film, are removed from the enamel surface.3, 5 This presumption is based on the multitude of endodontic literature supporting the use of NaOCl as an effective irrigant in root canal therapy6-13. In contrast to dentin and pulpal tissue, enamel is comprised of minimal organic matter.14, 15 As a result of this fact and the limited amount of experimentation of the effect of NaOCl on the enamel surface, the true mechanism by which sodium hypochlorite enhances the etching pattern of enamel is questionable.5, 16 The objective of this study was to determine the compositional effects of sodium hypochlorite on human enamel. Methods: Following IRB approval, 120 enamel sections from 22 extracted human premolar teeth were randomly divided into three experimental groups and one control group.17 The control group (E = enamel) received no treatment. The first experimental group (A = phosphoric acid) received a 15-second treatment with 37% phosphoric acid, rinsed with distilled water and air sprayed for 20 seconds, then dried with oil free compressed air. The second experimental group (H = sodium hypochlorite) received a treatment of 5.25% sodium hypochlorite for 60 seconds, washed with distilled water for 10 seconds, and dried. The third experimental group (HA = sodium hypochlorite + phosphoric acid) received a treatment of 5.25% sodium hypochlorite for 60 seconds, washed with distilled water for 10 seconds, dried, then receive the 15-second treatment with 37% phosphoric acid as in Group A.3 Following treatment preparations of the four groups, scanning electron microscopy (SEM)/energy-dispersive X-ray spectrometer (EDX) analysis was performed for all groups.18 For elemental concentration, a one-way ANOVA and Tukey’s post hoc statistical tests were applied.17, 19, 20 ANOVA and Tukey tests were performed at a significance level of p ≤ 0.05. Results: There were no significant effects of treatment on the enamel elements carbon (C), calcium (Ca) sodium (Na), oxygen (O), and phosphorous (P). There was a significant effect of treatment on the amount of chlorine (Cl) in enamel between groups acid (A) and hypochlorite + acid (HA) as well as between groups hypochlorite (H) and hypochlorite + acid (HA) (p = 0.004). The amount of variation of iodine (I) in the enamel composition between untreated enamel (E) and enamel treated with sodium hypochlorite + phosphoric acid (HA) was significant (p = 0.004). Additionally, there was a significant decrease in the quantity of antimony (Sb) found in the control group (E) versus the hypochlorite + acid (HA) experimental group (p = 0.002). Lastly, tin (Sn) was significantly reduced from the enamel surface (E) when treated with hypochlorite + acid (HA) (p = 0.008). Conclusions: The various treatments minimally affected the elemental concentrations of C, Ca, Na, O, and P. The amount of chlorine present in enamel significantly increased following treatment with sodium hypochlorite (H) alone and even more so following treatment with phosphoric acid and sodium hypochlorite (AH). In contrast, elements I, Sb, and Sn demonstrated a congruent reduction in concentration after treatment with hypochlorite and acid (HA). Although it has been hypothesized that sodium hypochlorite targets the organic pellicle present on the surface of enamel via a process known as deproteinization, the findings presented here suggest that pre-treatment with NaOCl impacts the inorganic components of enamel more so than the organic constituents. These quantitative findings corroborate the enhanced etching pattern that can be visualized under scanning electron microscopy in this as well as previous studies.