180 research outputs found
Compositionally and density stratified igneous terrain in Jezero crater, Mars
Before Perseverance, Jezero crater's floor was variably hypothesized to have a lacustrine, lava, volcanic airfall, or aeolian origin. SuperCam observations in the first 286 Mars days on Mars revealed a volcanic and intrusive terrain with compositional and density stratification.The dominant lithology along the traverse is basaltic, with plagioclase enrichment in stratigraphically higher locations. Stratigraphically lower, layered rocks are richer in normative pyroxene. The lowest observed unit has the highest inferred density and is olivine-rich with coarse (1.5 millimeters) euhedral, relatively unweathered grains, suggesting a cumulate origin. This is the first martian cumulate and shows similarities to martian meteorites, which also express olivine disequilibrium. Alteration materials including carbonates, sulfates, perchlorates, hydrated silicates, and iron oxides are pervasive but low in abundance, suggesting relatively brief lacustrine conditions. Orbital observations link the Jezero floor lithology to the broader Nili-Syrtis region, suggesting that density-driven compositional stratification is a regional characteristic.Funding was provided by the following sources: NASA's Mars exploration program, including contracts NNH15AZ24I and NNH13ZDA018O to LANL. LANL LDRD code XWHW contributed to calibrations. A portion of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). NASA RSSPS grants supported J.I.S., grantnumber 80NSSC20K0239 supported L. Hausrath, grant number 80NSSC20K0240 supported L. Mayhew, and grant number 80NSSC21K0330 supported A.U. CNRS and CNES supported the work in France. DLR supported S.Sc. and D.S.V. The Swedish National Space Agency (contracts 137/19 and 2021-00092) supported S.Si. The Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canadian Space Agency (CSA) supported E.C., S.C., and N.T. The Ministry of Economy and Competitiveness (MINECO, SPAIN) grant PID2019-107442RB-C31 supported F.R., G.L.R., J.A.M., and M
Use of portable devices and confocal Raman spectrometers at different wavelength to obtain the spectral information of the main organic components in tomatoes (Solanum Lycopersicum) fruits
Tomato (Solanum lycopersicum) fruit samples, in two ripening stages, ripe (red) and unripe (green), collected from a cultivar in the North of Spain (Barrika, Basque Country), were analyzed directly, without any sample pretreatment, with two different Raman instruments (portable spectrometer coupled to a micro-videocamera and a confocal Raman microscope), using two different laser excitation wavelengths (514 and 785 nm, only for the confocal microscope). The combined use of these laser excitation wavelengths allows obtaining, in a short period of time, the maximum spectral information about the main organic compounds present in this fruit. The major identified components of unripe tomatoes were cutin and cuticular waxes. On the other hand, the main components on ripe tomatoes were carotenes, polyphenoles and polysaccharides. Among the carotenes, it was possible to distinguish the presence of lycopene from b-carotene with the help of both excitation wavelengths, but specially using the 514 nm one, which revealed specific overtones and combination tones of this type of carotene.This work has been financially supported by Research Project S-PE11-UN128 of the Basque Country government. Technical and support provided by SGIker (UPV/EHU, MICINN, GV/EJ, ESF) is gratefully acknowledged
Analytical Techniques Applied to the Study of Industrial Archaeology Heritage: The Case of Plaiko Zubixe Footbridge
[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)
Soluble Salts Quantitative Characterization and Thermodynamic Modeling on Roman Bricks to Assess the Origin of Their Formation
The environmental weathering and the formation of efflorescences on the brick walls are studied at the “Casa di Diana” Mithraeum at Ostia Antica archaeological site. Previous studies on subsoil, bedrock, hydrological systems and environmental conditions, and new ion chromatography analysis combined with ECOS-RUNSALT and Medusa-Hydra thermodynamic modelling software, had allowed us to identify the subsoil contamination related to soluble salts. The atmospheric acidic gases, CO2 and SO2, are determined as the main salt weathering species. A dry deposition after a subsequent hydration action from the shallow freshwater aquifer that reaches up to 1 m on the walls is identified as the mechanism of salt formation. An evaluation of potential sources such as the nearby Fiumicino airport, CO2-rich gases inputs from fumaroles and CO2 inputs was also debated. The risk level of contamination the surfaces of the materials should be considered mildly/very polluted with a medium/high risk of hygroscopic moisture due to the high concentration of sulphates.This work has been supported by the DEMORA (Grant No. PID2020-113391GB-I00) projects funded by the Spanish Agency for Research AEI (MICINN/FEDER-UE)
Estudio Descriptivo Sobre La Influencia De Las Variables Personales Y El Fracaso Escolar En La Ciudad Autónoma De Melilla
The analysis of this study has been approached through a questionnaire. The questionnaire consists of two parts. The first is personal and academic data. The second part of the questionnaire contains 46 items. It is a Likert scale of four alternatives. For the statistical treatment of the data it was used SPSS v.21 for Windows. For the two-dimensional descriptive statistical analysis it was used the Mann-Whitney and Kruskal-Wallis programs. The most relevant contributions, in which the theoretical framework of this research is based, have been the Diagnostic and Statistical Manual of Mental Disorders, 2014 (DSM-5); Educational Law, especially that related to diversity, as well as the different contributions of studies and doctoral theses related to the investigation. From this study, intervention proposals and new lines of research will be carried out in order to reduce the high rate of failure and early school dropout in this city
Nature and origin of white efflorescence on bricks, artificial stones, and joint mortars of modern houses evaluated by portable Raman spectroscopy and laboratory analyses
Bricks and mortar currently constitute one of the most important building materials used in the
construction of most modern facades. The deterioration of these materials is caused primarily by the
impact of numerous external stressors, while poor manufacturing quality, particularly of mortars, can
also contribute to this process. In this work, the non-invasive Raman spectroscopy technique was used
to identify the recently formed deterioration compounds (primarily sulfates and nitrates) in bricks,
artificial stones, and joint mortars from detached houses in the Bilbao metropolitan area (Basque Country, North of Spain), as well as to investigate the deterioration processes taking place in these materials. Additionally, to confirm and in some cases complement the results obtained with Raman spectroscopy, SEM-EDS and XRD measurements were also carried out.This work was financially supported by DEMBUMIES (ref.BIA2011-28148) and funded by the Spanish Ministry of Economy and Competitiveness (MINECO). H. Morillas is grateful to the University of the Basque Country (UPV-EHU) and particularly to the UFI 11-26 Global Change and Heritage, who funded his pre-doctoral fellowship. Technical support provided by the Raman-LASPEA and General X-ray Service: Rocks and Minerals laboratories of SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) is also gratefully acknowledged
Reviewing in situ analytical techniques used to research Martian geochemistry: From the Viking Project to the MMX future mission
[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
Unraveling the role of the thermal and laser impacts on the blackening of cinnabar in the mural paintings of Pompeii
The blackening of red cinnabar (α-HgS) pigment has traditionally been explained by its conversion into black metacinnabar (β-HgS). Scarce is however the scientific evidence that supports this hypothesis in polychrome artworks. As such transition occurs at around 345 °C, the thermal impact of the eruption of Mount Vesuvius in 79 AD could have induced this structural change of the pigment present in the mural paintings of Pompeii. This work aims to assess whether the mentioned volcanic eruption could be responsible of the cinnabar blackening through the formation of metacinnabar. The thermodiffractometry study of cinnabar-decorated fresco mock-ups stated that the formed β-HgS is not stable, observing its reversion into α-HgS. Moreover, sublimation of the cinnabar pictorial layer was registered, also when the cinnabar paint layer was protected by a coating of pyroclastic materials. In real blackened cinnabar Pompeian samples, it was not possible to identify metacinnabar by X-ray diffraction (XRD), but evidence of sublimation of mercury due to the thermal impact was observed. Hence, this blackening seems to be related mainly to the presence of calomel (Hg2Cl2) and a gypsum (CaSO4·2H2O) crust as degradation products of red cinnabar and the calcite mortar, respectively, and not to the formation of metacinnabar. Finally, laser-based techniques could also induce modifications in the HgS crystalline structure, resulting in an amorphous black product. Therefore, the elemental and molecular study of the species promoted by laser impact was carried out to avoid false positives in the metacinnabar detection or when the decorated surface has been subjected to laser cleaning.The research leading to these results has received funding from “la Caixa” Foundation (Silvia Pérez-Diez, ID 100010434, Fellowship code LCF/BQ/ES18/11670017). This work has been supported by the project IT1446-22 for Consolidated Research Groups, funded by the Basque Country Government. The authors acknowledge as well the funding provided by University of the Basque Country through the Institutionally Sponsored Open Access
Portable and Raman imaging usefulness to detect decaying on mortars from Punta Begoña Galleries (Getxo, North of Spain)
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
Identification of metals and metalloids as hazardous elements in PM2.5 and PM10 collected in a coastal environment affected by diffuse contamination
The nature of the PM2.5 and PM10 varies enormously depending on the anthropogenic activities developed in the surrounding environment. These particles can include Hazardous Elements (HEs), such as
heavy metals, which can be considered dangerous for the human health. For this reason, determining the
nature of those HEs that are present in the surrounding atmosphere can help to comprehend possible
emission sources and to establish new strategies to reduce air pollution. In this work, a cost-effective
self-made passive sampler (SMPS) was tested as a tool to collect different size of PM containing
metals as HEs. The SMPS was installed in a 20th century historic building (Punta Begona Galleries, Getxo, ~
Basque Country, Spain), located just in front of the sea and thus, immersed in a coastal environment. This
location is affected by the activities developed in a marina and in a port, and by the diffuse influence of
several industries and a power station. The annual average for PM10 and PM2.5 were approximately 22 mg/
m3 and 10 mg/m3
, respectively. For develop this study, non-invasive elemental (Scanning Electron Microscope coupled to Energy Dispersive X-ray Spectrometry) and molecular (Raman microscopy) microspectroscopic techniques were used. Thanks to this methodology it was possible to determine in PM10
and PM2.5, the presence of heavy metals such as Fe, Cr, Ti, Pb, Zn, Ce, etc., most of them as oxides but also
embedded in different aggregations with aluminosilicates, phosphates, halides, sulfates, etc
- …