97 research outputs found

    Alterations and Contaminations in Ceramics Deposited in Underwater Environments: An Experimental Approach

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    Ancient ceramics recovered after a long burial period have probably undergone several alterations and contaminations, introducing a chemical variability, affecting the ceramic’s natural variability. That is, the chemical and the mineralogical compositions of the ceramic pastes after their deposition will not be the same as they originally were. Therefore, it is known that the alteration and contamination processes, and the discrimination of some elements, should be considered when studying the ceramics to avoid incorrect interpretations about their provenance, technology and the use of the artefact, as well as its proper preservation. In the present work, the authors performed an experimental approach in order to study the alterations and contaminations that occurred in 60 ceramic cylinders buried in two different underwater environments. Once the pieces were taken out from the water environments, they were characterized by a multi-analytical approach. For this purpose, inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), scanning electron microscopy–energy dispersive spectrometry (SEM–EDS) and Raman spectroscopy were used. Newly formed minerals of different forms have been identified, with different crystallization grades. Some examples are the needles, flakes, sponges and long and short prisms composed of several elements such as Ca, F, S and O.This research was funded by the Spanish Ministry of Economy, Industry and Competitiveness, the State Bureau of Investigation, and the European Regional Development Fund (MINECO/AEI/ERDF, UE), grant number CERANOR-2 (HAR2017-84219-P)

    Analytical Techniques Applied to the Study of Industrial Archaeology Heritage: The Case of Plaiko Zubixe Footbridge

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    [EN] In this work, micro-Raman spectroscopy and micro-energy-dispersive X-ray fluorescence spectroscopy (µ-EDXRF) were applied on microsamples taken from the Plaiko Zubixe footbridge (1927) located in Ondarroa (Basque Country, Spain) in order to investigate the original paint coating and make an evaluation of the conservation state before its restoration. Elemental and molecular images were acquired for the study of the compounds distribution. Some modern pigments such as phthalocyanine blue and green pigments, minium, calcium carbonate, Prussian blue, and hematite were identified. Barium sulfate and titanium dioxide were recognized as opacifier agents. Thanks to the study of the stratigraphies, it has been possible to determine the original paint layer, which includes lead white, ultramarine blue, carbon black, and barium sulfate. In addition, colorimetric analyses made it possible to know the CIELab values of the original layer in order to reproduce the original colour during the planned restoration work. The massive presence of chlorine detected by µ-EDXRF and the corrosion products of the rust layer, in particular akaganeite and hematite, highlighted the atmospheric impact in the conservation of the bridge because they were due to the effect of both marine aerosol and to the presence of acidic components in the environment coming from anthropogenic activity. This work demonstrated the usefulness of a scientific approach for the study of industrial archaeology heritage with the aim to contribute to its conservation and restorationThis research was funded by DEMORA project (Grant No. PID2020-113391GB-I00), funded by the Spanish Agency for Research (through the Spanish Ministry of Science and Innovation, MICINN, and the European Regional Development Fund, FEDER)

    Calcium inhibits diacylglycerol uptake by serum albumin

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    AbstractSerum albumin is an abundant protein in blood plasma, that is well-known for its ability to transport hydrophobic biomolecules and drugs. Recent hypotheses propose that serum albumin plays a role in the regulation of lipid metabolism in addition to its lipid transport properties. The present work explores the capacity of bovine serum albumin (BSA) to extract diacylglycerols (DAG) from phospholipid bilayers, and the inhibition of such interaction by divalent cations. Quantitative measurements using radioactive DAG and morphological evidence derived from giant unilamellar vesicles examined by confocal microscopy provide concurrent results. BSA extracts DAG from vesicles consisting of phosphatidylinositol/DAG. Long, saturated DAG species are incorporated more readily than the shorter-chain or unsaturated ones. Divalent cations hinder DAG uptake by BSA. For Ca2+, the concentration causing half-maximal inhibition is ≈10 μM; 90% inhibition is caused by 100 μM Ca2+. Sr2+ requires concentrations one order of magnitude higher, while Mg2+ has virtually no effect. As an example on how DAG uptake by BSA, and its inhibition by Ca2+, could play a regulating role in lipid metabolism, a PI-specific phospholipase C has been assayed in the presence of BSA and/or Ca2+. BSA activates the enzyme by removing the end-product DAG, but the activation is reverted by Ca2+ that inhibits DAG uptake

    Pottery making tradition in Logroño: an archaeometric approach to the Late Medieval workshops

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    This paper deals with the findings of Hospital Viejo site of Logroño (La Rioja, Spain), which yielded the largest evidence of local pottery production, comprising three kilns and a potters’ dump (13th–15th centuries). The study of pottery production in inland Iberia provides valuable information on the material conditions in which the Iberian medieval and post-medieval society occurred. Yet, the territory of La Rioja has been largely eclipsed by studies at coastal and southern areas of Iberia, due to their role in maritime exchange.With the aim of understanding the specific incidence and evolution of medieval pottery at regional scale, 77 sherds (MNI 637) including glazed and unglazed ware and kiln utensils were archaeometrically examined by combining the use of ICP-MS, XRD and SEM-EDS. Likewise, NAA was applied for provenance analysis, including the collation with a large majolica NAA database. The results provided the first chemical fingerprint of the production from Logroño consisting on three compositional groups within the same workshop (LOG-A, LOG-B and LOG-C). Moreover, pottery trading from Teruel and Valencia was detected, sustaining the historical records of these trade-networks. The imports showed tin lead glazes obtained by known recipes, contrasting with simpler manufactures (mostly unglazed or only lead glazed) of contemporary Logroño.DOKBERRI DOCREC19/39 (University of the Basque Country UPV/EHU), Ministerio de Economía y Competitividad CERANOR-2 (HAR2017-84219-P), Ministerio de Economía y Competitividad Ramon y Cajal (RYC-2014-16835), National Science Foundation grant #191277

    Ionogel-based Nitrite and Nitrate Sensor for Water Control at the Point-of-Need

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    Part of special issue: Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, HungaryThe increment of uncontrolled nutrients concentration in water is the subject of increasing environmental concern. In particular, the increment of nitrate causes the eutrophication of algae, leading to fauna and flora demise. In order to favour an easy and adequate monitoring of this environmental problem, we have developed an ionogel-based sensor for the colorimetric determination and image analysis detection of nitrite and nitrate in water. The sensor consists on a small poly(methyl)methacrilate (PMMA) device cut by a CO2 laser where both the detection and the calibration zones are integrated. A simple photograph of the whole device, followed by colour processing of the different sections of the chip was used for the determination of nitrite concentrations.The project was carried out with the support of the Ramón y Cajal programme (Ministerio de Economía y Competitividad). FBL, LAF-C and JS thank to the European Union‘s Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration under grant agreement no. 604241 for economical support. FBL acknowledges the Gobierno Vasco, Dpto. Industria, Innovación, Comercio y Turismo under ELKARTEK KK-2015/00088. Authors personally acknowledge Marian M. De Pancorbo for letting them to use her laboratory facilities at UPV/EHU

    Reviewing in situ analytical techniques used to research Martian geochemistry: From the Viking Project to the MMX future mission

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    [EN] The study of space has always been a field of great interest and thus space missions are becoming more and more ambitious with time. Therefore, with the 50th anniversary of the first spacecraft to land on Mars, a review about how traditional analytical techniques have been adapted to the era of in situ space exploration is presented. From the Viking Project to the future MMX mission, the techniques used for the in situ study of the geochemistry of the Martian surface is described. These techniques have been differentiated according to the type of analysis: elemental and molecular. On the one hand, among the elemental analytical techniques the XRF, APXS, ISE and LIBS stand out. On the other hand, GCMS, TEGA, MBS, XRD, Raman and IR spectroscopy have been the molecular techniques used in the missions to Mars. Miniaturization, real-time measurements, automation, low power consumption and reliability of operation under extreme conditions are some of the major challenges that analytical chemistry has faced as a result of the technological and scientific requirements of space missions. In this way, this review gathers all the in situ analytical techniques that have reached the surface of Mars onboard landers or rovers with the aim of studying its geochemistry.J. Huidobro is grateful to the Basque Government for her pre-doctoral contract. J. Aramendia is grateful to the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 754513 and the Aarhus University Research Foundation for her fellowship

    Portable and Raman imaging usefulness to detect decaying on mortars from Punta Begoña Galleries (Getxo, North of Spain)

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    Punta Begoña Galleries were built in 1918 in Getxo (Basque Country, North of Spain) but were abandoned in 1960. Nowadays, their conservation state is very poor. In this work, portable Raman spectroscopy was applied to evaluate the original composition and possible deterioration products of the mortars used in the inner walls and those covering the concrete of the ceilings allowing us to select the most appropriate sampling points. In the laboratory, Raman microscopy and Raman imaging, assisted with scanning electron microscopy equipped with an energy dispersive spectrometer (SEM‐EDS), X‐ray diffraction and energy dispersive X‐ray fluorescence (ED‐XRF) imaging, allowed to identify the key compounds to understand the deterioration processes taking place in the mortars of the galleries. The main components of the mortars from the walls were calcite and gypsum. In some cases, alite (Ca3SiO5) and belite (Ca2SiO4) were identified; these components are characteristic of Portland cement clinker. The main components of the mortar covering the concrete were calcite, quartz, aragonite and gypsum. The aragonite identification confirmed the use of beach sand as the aggregate in the mortar. The concrete from the ceiling of the lower gallery is covered with three different mortar layers; the outermost layer is covered with a black crust. In the three mortars, the main components are similar to those used in the mortar covering the concrete from the upper gallery. Thanks to Raman, ED‐XRF and SEM‐EDS imaging, it was possible to map the distribution of the main components through the three mortar layers and also to identify the presence of dolomite {[CaMg(CO3)2]}, which was not possible to detect following single‐point micro‐Raman analyses.This work has been funded by the Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF) through the project DISILICA‐1930 (ref. BIA2014‐59124‐P) and by the cooperation agreement between the University of the Basque Country (UPV/EHU) and the City Council of Getxo (OTRI2014‐0639). C. García‐Florentino is grateful to the University of the Basque Country (UPV/EHU), which funded her predoctoral fellowship. Technical support provided by Raman‐LASPEA Laboratory and General X‐ray Service of the SGIKer (UPV/EHU, Ministry of Economy and Competitiveness of Spain, Basque Government, ERDF and European Social Fund) is also gratefully acknowledged

    Improvement of Oil Valorization Extracted from Fish By-Products Using a Handheld near Infrared Spectrometer Coupled with Chemometrics

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    A handheld near infrared (NIR) spectrometer was used for on-site determination of the fatty acids (FAs) composition of industrial fish oils from fish by-products. Partial least square regression (PLSR) models were developed to correlate NIR spectra with the percentage of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs) and, among them, omega-3 (ω-3) and omega-6 (ω-6) FAs. In a first step, the data were divided into calibration validation datasets, obtaining good results regarding R2 values, root mean square error of prediction (RMSEP) and bias. In a second step, all these data were used to create a new calibration, which was uploaded to the handheld device and tested with an external validation set in real time. Evaluation of the external test set for SFAs, MUFAs, PUFAs and ω-3 models showed promising results, with R2 values of 0.98, 0.97, 0.97 and 0.99; RMSEP (%) of 0.94, 1.71, 1.11 and 0.98; and bias (%) values of −0.78, −0.12, −0.80 and −0.67, respectively. However, although ω-6 models achieved a good R2 value (0.95), the obtained RMSEP was considered high (2.08%), and the bias was not acceptable (−1.76%). This was corrected by applying bias and slope correction (BSC), obtaining acceptable values of R2 (0.95), RMSEP (1.09%) and bias (−0.05%). This work goes a step further in the technology readiness level (TRL) of handheld NIR sensor solutions for the fish by-product recovery industry.This research part of the “Gaitik -Monitoring of quality parameters for process automation: PAT technology for the improvement of production systems” project, funded by the Basque Government—Department of Economic Development, Sustainability and Environment—Vice. Dept. of Agriculture, Fishing and Food Policy, Directorate of Quality and Food Industries

    The Ychsma ceramic provenance from Armatambo, 1250 – 1532 CE (Lima, Peru). A local or imported production?

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    The Ychsma society was one of the most important civilizations developed between 900 and 1532 CE in Lima, the present Peruvian capital, situated on the central coast of Peru. The Ychsma territory included the lower basin of the Rímac and Lurín valleys in the current city of Lima (Peru). Around 1470 CE, the Ychsma region was conquered and placed under the control of the Inca Empire, which ruled the region until the Spanish conquest in 1532 CE. Despite this, the Inca rule allowed local elites to maintain their position and control of the population. The archaeological site of Armatambo was an important administrative center of the Ychsma society. This site was actively occupied during the Middle Ychsma (1250–1350 CE) and Late Ychsma (1350–1532 CE) phases, and as the capital of the Sullco Curacazgo controlled a large part of the lower Rímac valley. During excavations at this site, many materials associated with ceramic production were found. One aspect crucial to the study of ceramic materials is the reconstruction of ceramic production and distribution networks, which allows us to obtain information linked to the social and economic interaction between communities. To determine the local or non-local origin of the materials found at Armatambo, 61 samples were analyzed using ICP-MS, Petrography, and SEM. The results were compared with archaeological and geological data from the Rímac valley to determine whether or not production there was local or non-local and to identify possible sources of raw materials.The authors would like to acknowledge the funding granted by IDEX-Bordeaux which allowed the realization of the doctoral project. The funding of the Euroregion Nouvelle-Aquitaine/Euskadi-Navarra for the mobility funding (Dossier n°60161). Javier G. Iñañez thanks the Spanish Ministry of Economy and Competitiveness for a Ramon y Cajal contract (RYC-2014-16835)

    nuevos datos a partir de la arqueometria

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