20 research outputs found
Analytical tools applied to the evaluation of the influence of different marine environments on the conservation state of building materials
362 p.Marine aerosol is a chemical complex system formed by inorganic salts and organic matter, together with airborne particulate matter from the surrounding environment. The primary particles transported in the marine aerosol (PMA) can experiment different chemical reactions in the atmosphere, promoting the so-called Secondary Marine Aerosol (SMA) particles. These kinds of particles, together with the natural crustal or mineral particles and the metallic airborne particulate matter emitted by anthropogenic sources (road traffic, industry, etc.) can be deposited on building materials from a specific construction following dry deposition processes. Apart from that, the acid aerosols (e.g. CO2, SO2, NOX, etc.) present in modern urban-industrial environments, coming also from anthropogenic sources, could be deposited in the buildings following dry or a wet deposition mechanisms. The interactions of these natural and anthropogenic stressors with building materials can promote different kind of pathologies.In this PhD work, the negative influence of different marine environments (direct or diffuse influence), with or without the influence of an urban-industrial area (direct or diffuse), on the conservation state of two historical constructions and some newly built houses from the Basque Country (north of Spain) was evaluated. These constructions include a wide variety of building materials (sandstones, limestones, artificial stones, bricks, plasters, cementitious materials, etc.). The analytical methodology applied for this purpose involved, in some case studies, the use of non-invasive portable/hand-held spectroscopic technique (ED-XRF and Raman spectroscopy) able to perform an in situ screening in order to extract preliminary results. After that, non-invasive spectroscopic techniques (micro-Raman spectroscopy, FT-IR, XRD, -ED-XRF, SEM-EDS), together with destructive techniques (ICP-MS and ion chromatographic), thermodynamic modellings and chemometric tools was also applied to extract the final conclusions about the pathologies identified on the constructions under study in relation with the specific marine environment where they are located.Thanks to the use of these analytical tools, it was possible to characterize different deterioration processes caused mainly by the influence of marine aerosol (wet and dry deposition), infiltration waters, birds droppings, salts migrations, atmospheric acid gases impact, biological colonizations, etc. Moreover, the characterization of the PMA particles and SMA particles was conducted, thanks to the development of a home-made passive sampler in the last case. Additionally, the deposition of this kind of particles on sandstone, following dry deposition processes, was also confirmed
Analytical tools applied to the evaluation of the influence of different marine environments on the conservation state of building materials
362 p.Marine aerosol is a chemical complex system formed by inorganic salts and organic matter, together with airborne particulate matter from the surrounding environment. The primary particles transported in the marine aerosol (PMA) can experiment different chemical reactions in the atmosphere, promoting the so-called Secondary Marine Aerosol (SMA) particles. These kinds of particles, together with the natural crustal or mineral particles and the metallic airborne particulate matter emitted by anthropogenic sources (road traffic, industry, etc.) can be deposited on building materials from a specific construction following dry deposition processes. Apart from that, the acid aerosols (e.g. CO2, SO2, NOX, etc.) present in modern urban-industrial environments, coming also from anthropogenic sources, could be deposited in the buildings following dry or a wet deposition mechanisms. The interactions of these natural and anthropogenic stressors with building materials can promote different kind of pathologies.In this PhD work, the negative influence of different marine environments (direct or diffuse influence), with or without the influence of an urban-industrial area (direct or diffuse), on the conservation state of two historical constructions and some newly built houses from the Basque Country (north of Spain) was evaluated. These constructions include a wide variety of building materials (sandstones, limestones, artificial stones, bricks, plasters, cementitious materials, etc.). The analytical methodology applied for this purpose involved, in some case studies, the use of non-invasive portable/hand-held spectroscopic technique (ED-XRF and Raman spectroscopy) able to perform an in situ screening in order to extract preliminary results. After that, non-invasive spectroscopic techniques (micro-Raman spectroscopy, FT-IR, XRD, -ED-XRF, SEM-EDS), together with destructive techniques (ICP-MS and ion chromatographic), thermodynamic modellings and chemometric tools was also applied to extract the final conclusions about the pathologies identified on the constructions under study in relation with the specific marine environment where they are located.Thanks to the use of these analytical tools, it was possible to characterize different deterioration processes caused mainly by the influence of marine aerosol (wet and dry deposition), infiltration waters, birds droppings, salts migrations, atmospheric acid gases impact, biological colonizations, etc. Moreover, the characterization of the PMA particles and SMA particles was conducted, thanks to the development of a home-made passive sampler in the last case. Additionally, the deposition of this kind of particles on sandstone, following dry deposition processes, was also confirmed
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
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
Evaluation of black crust formation and soiling process on historical buildings from the Bilbao metropolitan area (north of Spain) using SEM-EDS and Raman microscopy
In the present work, several building materials suffering from black crusts and soiled surfaces were evaluated by scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDS) and micro-Raman spectroscopy. The goal was to examine the elemental and molecular composition, the distribution on the samples, and the morphology of endogenous and exogenous compounds on those black crusts and soiled surfaces. The black crusts were deposited over different building materials such as limestone, sandstone, and brick that constitute a small construction called "malacate" as well as over a limestone substrate of a cemetery gate. Both constructions are dated back to the beginning of the twentieth century. The samples of soiling were taken from the façade of a building constructed in the 1980s. The analytical evaluation allowed in a first stage the determination of the composition and the observation of the morphology of soiling and black crusts. In addition, the evaluation of the compositions of the soiling and black crusts of different grade and formation allowed the assessment of the main weathering phenomena that the buildings have suffered, which were found to be sulfate impact, marine aerosol impact, depositions of metallic particles, crustal particulate matter depositions, carbonaceous particles, biodeterioration, and vandalism.This work has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project DISILICA-1930 (ref. BIA2014-59124-P) and the Regional Development Fund (FEDER). E. Calparsoro is grateful also to the Spanish Ministry of Economy and Competitiveness (MINECO) who funded his pre-doctoral fellowship (ref. BES-2014-068940)
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
Non-Adherence in Adult Male Patients with Community-Acquired Pneumonia: Relative Forgiveness of Amoxicillin versus Respiratory Fluoroquinolones
The consequences of non-adherence to treatment (NAT) on antimicrobial efficacy may depend on drug forgiveness—a property that should account for pharmacokinetics (PK) and pharmacodynamics (PD) as well as interindividual variability. In this simulation study, relative forgiveness (RF) in NAT, defined as the probability of a successful PK/PD target (PTA) attained under perfect adherence compared to imperfect adherence, was evaluated for amoxicillin (AMOX) (oral 1000 mg/8 h) and two respiratory fluoroquinolones—levofloxacin (LFX) (oral 750 mg/24 h) and moxifloxacin (MOX) (oral 400 mg/24 h)—in virtual outpatients with community-acquired pneumonia for S. pneumoniae. Several NAT scenarios (delay in dose intake and a missed dose) were considered. PK characteristics of virtual patients, including variability in creatinine clearance (70–131 mL/min) and S. pneumoniae susceptibility variability associated with geographical location, were simulated in NAT. In this regard, in regions of low MIC delays from 1 h to 7 h or omission of dose ingestion would not have negative consequences on the efficacy of AMOX because of its good RF associated with the AMOX PK and PD properties; RF of LFX 750 mg or MOX 400 mg/24 h regimen vs. AMOX 1000 mg/8 h is one. However, in regions of elevated MIC for S. pneumoniae AMOX loses its RF, LFX and MOX vs. AMOX, showing higher RF (>1) depending on the CLCR of patients. These results illustrate the importance of considering the RF of antimicrobial drugs in NAT and provide a framework for further studying its implications for clinical success rates
Multianalytical Approach to explain the darkening process of hematite pigment in paintings from ancient Pompeii after accelerated weathering experiments
[EN] In this paper, recently excavated fresco painting fragments from the House of Marcus Lucretius (Pompeii) and not exposed to the atmosphere since the eruption of the Mount Vesuvius were subjected to a controlled SO2 atmosphere and high relative humidity. These experiments were conducted in order to simulate under accelerated conditions the possible deterioration of the hematite pigment and plaster. The mineralogical transformation of the polychromy and plaster was monitored using mainly Raman spectroscopy, a non-destructive technique, but also infrared spectroscopy (FT-IR) and scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM-EDS). After different exposure cycles to SO2, it was confirmed that hematite red pigment (Fe2O3) can be reduced into magnetite (Fe3O4), which provides the darkened colour to the pigment. While Fe(III) from hematite is reduced into Fe(II) or mixed Fe(III) and Fe(II), the SO2 can be oxidized (SO3) and hydrated to experience a subsequent wet deposition (H2SO4 aerosol) causing also the transformation of calcite into gypsum. Finally, it was assessed that high concentrations of SO2 can also cause the sulphation of hematite pigment promoting its transformation into paracoquimbite/coquimbite (Fe2(SO4)3$9H2O). Moreover, in some areas of the deteriorated painting fragments, non-expected iron(II) sulphate and sulphite species were also identified
Elemental imaging approach to assess the ability of subaerial biofilms growing on constructions located in tropical climates as potential biomonitors of atmospheric heavy metals pollution
Over the last decades, the concern about air pollution has increased significantly, especially in urban areas. Active sampling of air pollutants requires specific instrumentation not always available in all the laboratories. Passive sampling has a lower cost than active alternatives but still requires efforts to cover extensive areas. The use of biological systems as passive samplers might be a solution that provides information about air pollution to assist decision-makers in environmental health and urban planning. This study aims to employ subaerial biofilms (SABs) growing naturally on façades of historical and recent constructions as natural passive biomonitors of atmospheric heavy metals pollution. Concretely, SABs spontaneously growing on constructions located in a tropical climate, like the one of the city of Barranquilla (Colombia), have been used to develop the methodological approach here presented as an alternative to SABS grown under laboratory conditions. After a proper identification of the biocolonizers in the SAB through taxonomic and morphological observations, the study of the particulate matter accumulated on the SABs of five constructions was conducted under a multi-analytical approach based mainly on elemental imaging studies by micro Energy Dispersive X-ray fluorescence spectrometry (μ-EDXRF) and Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectrometry (SEM-EDS) techniques, trying to reduce the time needed and associated costs. This methodology allowed to discriminate metals that are part of the original structure of the SABs, from those coming from the anthropogenic emissions. The whole methodology applied assisted the identification of the main metallic particles that could be associated with nearby anthropogenic sources of emission such as Zn, Fe, Mn, Ni and Ti by SEM-EDS and by μ-EDXRF Ba, Sb, Sn, Cl and Br apart others; revealing that it could be used as a good alternative for a rapid screening of the atmospheric heavy metals pollution.This work has been supported by the project IT1446-22 for Research Groups of the Basque University System, funded by the Basque Country Government. Open Access funding provided by University of the Basque Country is also gratefully acknowledged. The authors thank for technical and human support provided by SGIker (UPV/EHU/ERDF, EU) and concretely to Alfredo Sarmiento from Coupled Multispectroscopy Singular Laboratory (Raman-LASPEA)
Elucidation of the Chemical Role of the Pyroclastic Materials on the State of Conservation of Mural Paintings from Pompeii
Pyroclastic strata have always been thought to protect the archaeological remains of the Vesuvian area (Italy), hence allowing their conservation throughout the centuries. In this work, we demonstrate that they constitute a potential threat for the conservation state of the mural paintings of Pompeii. The ions that could be leached from them and the ion‐rich groundwater coming from the volcanic soil/rocks, may contribute to salt crystallisation. Thermodynamic modelling not only allowed to predict which salts can precipitate from such leaching events, but also assisted the identification of additional sources of sulfates and alkali metals, to explain the formation of the sulfates identified in efflorescences from the mural paintings of Pompeii. For the future, fluorine, mainly related to a volcanic origin, can be proposed as a marker to monitor in situ the extent of the impact in the mural paintings of Pompeii.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 projects MADyLIN (Ministry of Economy, Industry and Competitiveness from Spain, Grant No. BIA2017‐87063‐P) funded by the Spanish Agency for Research AEI (MINECO-FEDER/UE) and MINECO-17-CTQ2016-77887-C2-1-R