Ascertaining the degradation state of ceramic tiles : a preliminary non-destructive step in view of conservation treatments

Conserving the cultural heritage is a general concern and the use of non-destructive techniques to characterize ancient materials is important. Serious deterioration effects in environmentally exposed ancient glazed ceramic tiles arise from the development of micro-organisms (algae/fungi) within the pore system. Subsequent biodegradation processes are particularly harmful once the decorated glaze is damaged by exfoliation/detachment. Three case studies will be addressed: Portuguese polychrome decorated tiles from the interior of two churches (16th–17th century) and from the outdoor of a Palace (18th century). Small tile fragments were directly irradiated in a wavelength-dispersive X-ray fluorescence spectrometer for glaze chemical characterization and subsequently irradiated in a powder diffractometer to assess the phase constitution of both glaze and ceramic body. Cleaning and conserving these ancient cultural artifacts involve a decontamination process applying innovative non-destructive techniques. The present work is intended as a contribution to diagnose the actual degradation state of ancient tiles in view of future decontamination actions using gamma radiation

Luminiscence dating of burial 3 and the bell beaker pottery from La Pijotilla (Badajoz, Spain)

La Pijotilla es uno de los mayores asentamientos (80 Ha) del III milenio A.N.E. de la Península Ibérica, siendo considerado un lugar central dentro de la red de poblamiento de Tierra de Barros (comarca de Tierra de Barros, Badajoz). Desde los años 70 se han excavado el poblado y la necrópolis, destacando la tumba T3, excavada en la roca donde se realizaron 300 inhumaciones en capas sucesivas generando una estratigrafía amplia y que contenía un variado y cuantioso ajuar. En el poblado se ha recuperado una colección de fragmentos campaniformes sin contexto estratigráfico, junto a una gran diversidad de estilos decorativos pertenecientes a la última fases del III milenio ANE. El objetivo propuesto en este trabajo ha sido datar diferentes niveles de la tumba T3 y compararlas con otras dataciones C14; al igual que datar la cerámica campaniforme de superficie del poblado y compararla con dataciones absolutas procedentes de contextos habitacionalesLa Pijotilla, one of the largest settlements through out all Iberian Peninsula, and is considered a central place of Tierra de Barros Copper Age settlement network (Comarca de Tierra de Barros, Badajoz). During the field works that has been going on since the 70’s, the settlement and the necropolis area have been located. Several tombs have been excavated, standing out tomb 3, build on the rock with 300 buried individuals and a great richness of funerary objects alternated in several layers. During survey works in the settlement a large amount of decorated pottery from III millennium BC including a great number of Bell Beaker pottery, without a stratigraphic context, have been found. The focus in this work is to date different layers of T3 using luminescence techniques and compare them with old and new radiocarbon dates, as well as to date the survey-collected Bell Beaker pottery and compare them with the settlement radiocarbon datesPlan Nacional de Materiales MAT 2005-000790GRICES-CSIC 2005-PT003

Diagnosis of pathologies in ancient (seventeenth-eighteenth centuries) decorative blue-and-white ceramic tiles : Green stains in the glazes of a panel depicting Lisbon prior to the 1755 earthquake

Decorative panels of ceramic glazed tiles comprise a valuable cultural heritage in Mediterranean countries. Their preservation requires the development of a systematic scientific approach. Exposure to an open-air environment allows for a large span of deterioration effects. Successfully overcoming these effects demands a careful identification of involved degradation processes. Among these, the development of micro-organisms and concomitant glaze surface staining is a very common effect observed in panels manufactured centuries ago. This paper describes a study on the nature of green stains appearing at the surface of blue-and-white tile glazes from a large decorative panel with more than one thousand tiles, called Vista de Lisboa that depicts the city before the destruction caused by the 1755 earthquake. The characterization of green-stained blue-and-white tile glazes was performed using non-destructive X-ray techniques (diffraction and fluorescence spectrometry) by directly irradiating the surface of small tile fragments, complemented by a destructive scanning electron microscopy (SEM) observation of one fragment. Despite the green staining, analytical X-ray data showed that no deterioration had occurred irrespective of the blue or white color, while complementary SEM-EDX data provided chemical evidence of microorganism colonization at the stained glaze surface

Chemistry of volcanic soils used for agriculture in Brava Island (Cape Verde) envisaging a sustainable management

In order to acquire a better knowledge of iron forms, clay minerals and the content and distribution of trace elements in soils mostly used for agriculture in the semi-arid Brava Island (Cape Verde), iron speciation, mineralogy and chemical contents in the clay-size fraction (<2 μm) of incipient soils developed on sediments and phonolitic pyroclasts was performed by Mössbauer spectroscopy, X-ray diffraction and neutron activation analysis. In contrast with the whole samples in the clay-size fraction of all the studied soils only Fe(III) was detected. Iron and chromium are depleted suggesting their occurrence as ferromagnesian and oxide minerals present in coarser particles. Rare earth elements are concentrated in the clay-size fraction, and significant differences are found in their distribution which may be partially due to oxidation, since Ce anomalies were observed. Among the other chemical elements studied, high concentrations of arsenic, bromine, and particularly antimony were found in the clay-size fraction of soils where all the Fe oxides are nano-sized, confirming the predominant adsorption of these elements on the nano-particles surface. The existence of significant amounts of these elements as well as of vitreous phases in fine particles of these soils may contribute to their mobility and accumulation in groundwater and in plants, both by absorption and by dust deposition onto the plant leaves.publishe

Antibiotic resistance in wastewater: Occurrence and fate ofEnterobacteriaceaeproducers of Class A and Class C β-lactamases

Antibiotics have been intensively used over the last decades in human and animal therapy and livestock, resulting in serious environmental and public health problems, namely due to the antibiotic residues concentration in wastewaters and to the development of antibiotic-resistant bacteria. This study aimed to access the contribution of some anthropological activities, namely urban household, hospital and a wastewater treatment plant, to the spread of antibiotic resistances in the treated wastewater released into the Mondego River, Coimbra, Portugal. Six sampling sites were selected in the wastewater network and in the river. The ampicillin-resistant Enterobacteriaceae of the water samples were enumerated, isolated and phenotypically characterized in relation to their resistance profile to 13 antibiotics. Some isolates were identified into species level and investigated for the presence of class A and class C -lactamases. Results revealed high frequency of resistance to the -lactam group, cefoxitin (53.5%), amoxicillin/clavulanic acid combination (43.5%), cefotaxime (22.7%), aztreonam (21.3) cefpirome (19.2%), ceftazidime (16.2%) and to the non--lactam group, trimethoprim/sulfamethoxazol (21.1%), tetracycline (18.2%), followed by ciprofloxacin (14.1%). The hospital effluent showed the higher rates of resistance to all antibiotic, except two (chloramphenicol and gentamicin). Similarly, higher resistance rates were detected in the wastewater treatment plant (WWTP) effluent compared with the untreated affluent. Regarding the multidrug resistance, the highest incidence was recorded in the hospital sewage and the lowest in the urban waste. The majority of the isolates altogether are potentially extended-spectrum -lactamases positive (ESBL(+)) (51.9%), followed by AmpC(+) (44.4%) and ESBL(+)/AmpC(+) (35.2%). The most prevalent genes among the potential ESBL producers were blaOXA (33.3%), blaTEM (24.1%) and blaCTX-M (5.6%) and among the AmpC producers were blaEBC (38.9%), blaFOX (1.9%) and blaCIT (1.9%). In conclusion, the hospital and the WWTP activities revealed to have the highest contribution to the spread of multidrug resistant bacteria in the study area. Such data is important for future management of the environmental and public health risk of these contaminants. This is the first embracing study in the water network of Coimbra region on the dissemination of antibiotic resistance determinants. Moreover, it is also the first report with the simultaneous detection of multiresistant bacteria producers of AmpC and ESBLs -lactamases in aquatic systems in Portugal.info:eu-repo/semantics/publishedVersio

The adaptation of the main floor of the Palace Melo e Abreu (18th century) to an infirmary of the old asylum of mendicity: history and tile panels compositional characterization

Due to its sunny location and mild climate, the hill of Sant'Ana in Lisbon was, since early times, the place of construction of religious and civil buildings. In the eighteenth century, near the former Santo António dos Capuchos Convent (later Hospital – HSAC), a Baroque palace was erected and later on rebuilt by the Melo e Abreu family (later Condes de Murça in the 19th century), whose noble rooms were decorated by a set of high quality tiles, concerned with iconographic and plasticity aspects. The transfer of the Melo e Abreu family to the parish of Santos-o-Velho and subsequent founding of the Asilo da Mendicidade, allowed the purchase of the building in order to expand the assistance space. Currently, the palace serves hospital’s needs, with all the constraints resulting from the cohabitation between cultural heritage and professional medical care day life. Thus, Palace Melo e Abreu is a good case study, not only for the functional changes that it has been subjected to, but also for the rehabilitation measures for structural restoration and conservation made over time. For the assessment of its importance in terms of both heritage and scientific history, we will present an interdisciplinary study, including History of Art and Archaeometry; In this work (together with the history of the adaptation of the main floor of the Palace Melo e Abreu to an infirmary of the old asylum of mendacity) a first stage of the archaeometric approach is presented, comprising the compositional characterization (chemical and mineralogical) of both mortar and glazed tile body of selected panels. We believe that this paper will promote a deep reflection about the safeguard and future heritage policies of this kind of Lisbon's hospitals.info:eu-repo/semantics/publishedVersio

Geochemial patterns and firing technology research on ceramic glazed tiles from the 17th-20th centuries (Lisbon region, Portugal)

A set of 17th – 20th century glazed tiles supplied by the Department of Cultural Heritage tile collection, Lisbon City Hall, is studied in this work. The tiles were described and classified in a chronological point of view and analytical work includes chemical and mineralogical characterization of the ceramic bodies and mortars by instrumental neutron activation analysis and X-ray diffraction. Most tile bodies consist mainly of quartz, gehlenite and calcite in variable proportions; commonly these main phases are accompanied by high temperatures phases, namely wollastonite or diopside, pointing to a Ca- or Mg-rich raw material, and mullite (in one sample) indicating the use of non-carbonated raw materials. Small amounts of K-feldspar and hematite are present in most tiles, whereas analcime, plagioclase, vaterite and cristobalite are found in just a few samples. Chemical composition points to a certain homogeneity within 18th century tile bodies; the 20th century samples analysed are heterogeneous and have a different rare earth elements (REE) pattern, two are enriched in the first transition row elements, pointing to higher amounts of ferromagnesian minerals, and the other has lower amounts of Na, Fe, Cr and Co, and higher of Cs, light rare earth elements (LREE), Th and U suggesting high aluminium silicates content. The 17th century samples have a more heterogeneous chemical composition and higher contents of As and Na, which is explained by the presence of analcime. The ancient tiles have a general depletion of chemical elements, probably due to a dilution effect of the higher calcite content. The mortars are all lime rich, but the 20th century ones have a general enrichment in all elements, and more k-feldspar and mica.info:eu-repo/semantics/publishedVersio

Distribution and chronological framework for Iberian variscite mining and consumption at Pico Centeno, Encinasola, Spain

AMS radiocarbon and OSL dating, and profiling were used to directly delimit periods of variscite production at Pico CentenoMine 2. These resultswere integratedwith analysis of otherwell-dated periods of variscite production to establish an Iberian-wide chronological framework. Variscite production at Pico Centeno Mine 2 began at ~5200 BC, coincident with alpine jade production or Casa Montero Iberian flint production. Variscite was only used occasionally, together with other greenstones, during the 5th and 6th millennia BC. During the 4thmillenniumBC, variscite use began to increase to its apogee in the first half of 3rd millenniumBC when it appeared in nearly every Iberian burial site. This increase in variscite production and use coincided with decline in the popularity of alpine jade. By the end of the 3rd millennium BC, new resources began to be valued such as Asian and African Ivory, Baltic and Sicilian amber, and copper-based metal products. The variscite cycle thus started with the decline of jade in the 5th–4th millennium BC, and ended with the appearance of copper, ivory and extra-peninsular amber by the end of the 3rd millennium BC.info:eu-repo/semantics/publishedVersio