76 research outputs found
Development of in situ non destructive analytical methodologies for the conservation diagnosis of urban built heritage
226 p.Se desarrollan metodologías analíticas no destructivas para el diagnostico in situ del Patrimonio Construido afectado por factores ambientales. A lo largo del trabajo, la caracterización y severidad de daño sufrido por los materiales es evaluada en casos reales, prestando especial atención a establecer el origen y el proceso químico involucrado en las patologías, contribuyendo a la preservación. Además, para comprobar la efectividad de un innovativo método de conservación, se realiza su monitoreo a través de un enfoque multianalítico, evaluando su capacidad para reducir el deterioro así como, para determinar los requerimientos para su implementación.Las metas propuestas han sido logradas gracias al desarrollo de diferentes metodologías, destacando la utilidad de la espectroscopia Raman. Los hándicaps resultantes del análisis de campo han sido reducidos gracias a la implementación de DRIFT. Paralelamente, técnicas como SEM y XRF han sido propuestas para detectar la capacidad de penetración de los agentes de deterioro así como, IC para cuantificar la severidad del daño salino, de acuerdo a la legislación existente. A sí mismo, los datos cuantitativos son sometidos a estudios quimiométricos y termodinámicos con objeto de corroborar el análisis espectroscopico. Finalmente, dadas las diferencias observadas en los análisis por cambios estacionales, se llevo a cabo un estudio para describir el comportamiento del contenido salino bajo condiciones climáticas variables con objeto de seleccionar las acciones preventivas, evitando la necesidad de tomar decisiones solamente basadas en la experiencia del conservador
Development of in situ non destructive analytical methodologies for the conservation diagnosis of urban built heritage
226 p.Se desarrollan metodologías analíticas no destructivas para el diagnostico in situ del Patrimonio Construido afectado por factores ambientales. A lo largo del trabajo, la caracterización y severidad de daño sufrido por los materiales es evaluada en casos reales, prestando especial atención a establecer el origen y el proceso químico involucrado en las patologías, contribuyendo a la preservación. Además, para comprobar la efectividad de un innovativo método de conservación, se realiza su monitoreo a través de un enfoque multianalítico, evaluando su capacidad para reducir el deterioro así como, para determinar los requerimientos para su implementación.Las metas propuestas han sido logradas gracias al desarrollo de diferentes metodologías, destacando la utilidad de la espectroscopia Raman. Los hándicaps resultantes del análisis de campo han sido reducidos gracias a la implementación de DRIFT. Paralelamente, técnicas como SEM y XRF han sido propuestas para detectar la capacidad de penetración de los agentes de deterioro así como, IC para cuantificar la severidad del daño salino, de acuerdo a la legislación existente. A sí mismo, los datos cuantitativos son sometidos a estudios quimiométricos y termodinámicos con objeto de corroborar el análisis espectroscopico. Finalmente, dadas las diferencias observadas en los análisis por cambios estacionales, se llevo a cabo un estudio para describir el comportamiento del contenido salino bajo condiciones climáticas variables con objeto de seleccionar las acciones preventivas, evitando la necesidad de tomar decisiones solamente basadas en la experiencia del conservador
TECHNART 2017. Non-destructive and microanalytical techniques in art and cultural heritage. Book of abstracts
440 p.TECHNART2017 is the international biannual congress on the application of Analytical Techniques in Art and Cultural Heritage. The aim of this European conference is to provide a scientific forum to present and promote the use of analytical spectroscopic techniques in cultural heritage on a worldwide scale to stimulate contacts and exchange experiences, making a bridge between science and art.
This conference builds on the momentum of the previous TECHNART editions of Lisbon, Athens, Berlin, Amsterdam and Catania, offering an outstanding and unique opportunity for exchanging knowledge on leading edge developments.
Cultural heritage studies are interpreted in a broad sense, including pigments, stones, metal, glass, ceramics, chemometrics on artwork studies, resins, fibers, forensic applications in art, history, archaeology and conservation science.
The meeting is focused in different aspects:
- X-ray analysis (XRF, PIXE, XRD, SEM-EDX).
- Confocal X-ray microscopy (3D Micro-XRF, 3D Micro-PIXE).
- Synchrotron, ion beam and neutron based techniques/instrumentation.
- FT-IR and Raman spectroscopy.
- UV-Vis and NIR absorption/reflectance and fluorescence.
- Laser-based analytical techniques (LIBS, etc.).
- Magnetic resonance techniques.
- Chromatography (GC, HPLC) and mass spectrometry.
- Optical imaging and coherence techniques.
- Mobile spectrometry and remote sensing
Detección de compuestos orgánicos mediante LIBS en rocas de interés en exploración planetaria. Aplicaciones en Astrobiología
La integración de instrumentos LIBS en misiones de exploración planetaria es una realidad desde hace ya unos años, siendo una tecnología conducente a la obtención de información multielemental en las distintas rocas y minerales existentes en la superficie de Marte. Su gran eficacia ha sido demostrada en muchos de los trabajos publicados hasta la fecha por los equipos de investigación participantes en la misión Mars Science Laboratory (MSL). Uno de los objetivos primordiales de dichas investigaciones radica en la detección de posibles bioindicadores [1], así como en la identificación y discriminación mediante LIBS de compuestos orgánicos, tarea que puede llegar a ser compleja ya que, entre otros aspectos, se trata de una técnica muy sensible a las condiciones ambientales (composición de la atmósfera y presión existente) [2] [3].
El presente trabajo ha buscado por un lado, evaluar el efecto de la atmósfera existente en el planeta rojo (rica en CO2 con 7mb de presión media) en la formación de plasmas inducidos por láser a partir de la ablación de muestras formadas por matrices inorgánicas dopadas con compuestos orgánicos seleccionados. Por otro lado, a partir de las diferentes huellas espectrales obtenidas en dichas condiciones y mediante la aplicación de técnicas quimiométricas adaptadas, se estudian las posibilidades de identificación de dichos referentes orgánicos.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Laser-induced breakdown spectroscopy of cyanobacteria in carbonate matrices under simulated Martian environment
The finding on the Martian surface of hydrated salt minerals, like carbonates and sulphates, and their interpretation as deriving from the desiccation of old bodies of water, has provided an evidence of liquid water activity on the surface of Mars [1]. These evaporite environments and their saline deposits are now a chief goal for planetary missions devoted to the search for fossil Martian life. Such minerals have the possibility of trapping and preserving over geologic times a biological record made up of halophilic extremophiles [1]. The existence of species of cyanobacteria that inhabit rock substrates on Earth, capable of growing in environments considered extreme, makes them ideal organisms for studying biological responses in different environmental conditions [2]. One possible organism detection strategy consists in the study of the most relevant emission lines and molecular bands attributed to presence of life by laser-induced breakdown spectroscopy (LIBS). However, the detection of these species can be complex as LIBS is sensitive to environmental conditions, such as the atmosphere composition and pressure, and could contribute to this signal [3].
In the present study, several species of cyanobacteria with dissimilar extremophilic characteristics [4] (tolerance to desiccation and salinity) were examined by LIBS. The identification and discrimination of cyanobacteria on carbonate substrates was based on organic signal emissions (C, C2, CN...) and the presence of other microelements (Fe, Si, Cu, K…). For this purpose, and to evaluate the influence of the surrounding atmosphere on the plasma composition and its contribution on LIBS signal, a set of samples including Arthrospira platensis (commercial), Microcystys aeruginosa (cultured) and Chroococcidiopsis sp. (natural samples) was analyzed under i) Mars-analogue atmosphere and ii) low air vacuum (7mbar)Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Searching for Biosignatures in Mars by LIBS Molecular Signals Discernment
In the present study, LIBS analysis of a set of six selected molecules related to organic biosignatures -or their degradation compounds- have been carried out in both simulated Martian atmosphere and air in order to identify and discriminate them on the basis of their molecular emission features.
This strategy can reveal insights into how different emission spectral modes react to changes in atmospheric conditions and therefore can help to detect those species which are more sensitive to changes in pressure and composition of the atmosphere. At high laser irradiance, atomization of organic compounds is essentially complete, although at sufficiently delayed integration times, the formation of new molecules by recombination processes can be noticed[1]. Molecular species characteristic of organic emissions such as C2, CN, NH, OH and CH were studied. Results can contribute to establish the optimal conditions for the observation of organic carbon species in laser-induced plasmas and the bases for the ensuing detection of organic biosignatures in analogous geological materials from Mars. Likewise, this research is aimed at providing a tool in the interpretation of LIBS data though the application of adapted data processing algorithms for the identification and discernment of suspected compounds of organic nature[2]
[1] T. Delgado, L. García-Gómez, L. M. Cabalín, J. J. Laserna, Investigation on the origin of molecular emissions in laser-induced breakdown spectroscopy under Mars-like atmospheric conditions of isotope-labeled compounds of interest in astrobiology, Spectrochim. Acta Part B (2021) 179-106114.
[2] T. Delgado, L. García-Gómez, L. M. Cabalín, J. J. Laserna, Detectability and discrimination of biomarker organic precursors in a low pressure CO2 atmosphere by LIBS, J. Anal. At. Spectrom. (2020) 35:1947.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Thermodynamic Solution Properties of a Biodegradable Chelant (L-glutamic-N,N-diacetic Acid, L-GLDA) and Its Sequestering Ability toward Cd2+
The thermodynamics of the interaction of L-glutamic-N,N-diacetic acid (GLDA) with protons was studied potentiometrically at different temperatures, ionic strengths and ionic media. Four protonation constants and corresponding enthalpy changes occurred at infinite dilution together with temperature and ionic strength coefficients. The medium effect was also interpreted in terms of the formation of weak complexes between the ligand and the cations of supporting electrolytes, resulting in a greater tendency of GLDA to chemically interact with Na+ rather than K+ and, in turn, (CH3)4N+. Formation constants of GLDA with Cd2+ were determined in NaCl(aq) at different ionic strength values. Five complex species were found, namely CdL2−, CdHL−, CdH2L0(aq), Cd2L0(aq), and Cd(OH)L3−, whose formation constant values at infinite dilution were log β = 12.68, 17.61, 20.76, 17.52, and 1.77, respectively. All the species results were relevant in the pH range of natural waters, although the Cd2L0(aq) was observed only for CCd ≥ CGLDA and concentrations of >0.1 mmol dm−3. The sequestering ability of GLDA toward Cd2+, evaluated by means of pL0.5, was maximum at pH~10, whereas the presence of a chloride containing a supporting electrolyte exerted a negative effect. Among new generation biodegradable ligands, GLDA was the most efficient in Cd2+ sequestration.The authors C.B., P.C., A.I., G.L. and C.D.S. thank the University of Messina for the Research and Mobility 2017 Project (cod. 009041). Authors thank COST action CA18202—Network for Equilibria and Chemical Thermodynamics Advanced Research for the support to this study. O.G.-L. is grateful to the project IT-742-13 for Consolidated Research Groups, funded by the Basque Country Government, for her post-doctoral contract
Sugar-derived bio-based resins as platforms for the development of multifunctional hybrids with potential application for stone conservation
This research is focused on the design of a bio-based epoxy-silica hybrid, enriched with SiO2 nanoparticles, to be used in stone conservation. For this purpose, isosorbide, a sugar derivative coming from renewable sources, was selected for the development of epoxy thermosets that were functionalized adding fixed amounts of silicaforming mixtures, to gain hybrid organic-inorganic networks. Fourier Transform Infrared (FTIR), Attenuated Total Reflection Infrared (ATR-FTIR) and Raman spectroscopies were exploited to follow the synthetic procedures, whereas the homogeneity of the networks was ascertained by scanning electron microscopy/energydispersive X-ray spectroscopy (SEM-EDS). The materials were investigated by thermogravimetric (TG-DTA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and contact angle measurements. Once the proper epoxy-silica product was identified, specifically synthesized nanoparticles were incorporated. The obtained nanocomposite showed excellent thermo-mechanical (Tonset, Tg and Tα of 327, 55.9 and 70.1 ◦C, respectively) and hydrophobic (105◦) properties making it a potential candidate for stone conservation.This work has been financially supported by the project PHETRUM (CTQ2017-82761-P) from the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) and by the European Regional Development Fund (FEDER). The authors gratefully acknowledge Open Access funding provided by University of Basque Country. P. Irizar gratefully acknowledges his predoctoral grant from the MINECO (PRE2018-085888). O. Gomez-Laserna is grateful to the projects IT-742-13 for Consolidated Research Groups, funded by the Basque Country Government, and PHETRUM (CTQ2017-82761-P) from the MINECO for her post-doctoral contract. P. Cardiano thanks the Italian Ministry of University and Research (MIUR), PON R&I project AGM for CuHe (ARS01_00697), for Contact Angle measurements. The authors are grateful to the technical support provided by the Raman-LASPEA laboratory, the Nuclear Magnetic Resonance laboratory and to the Macrobehaviour, Mesostructure, Nanotechnology: Unit of Materials and Surfaces of The Advanced Research Facilities of the SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF)
La influencia de la responsabilidad social de las empresas en el comportamiento de compra de los consumidores en Colombia
La presente investigación pretende determinar la incidencia que tienen la
Responsabilidad Social Empresarial en el comportamiento de compra y en la disposición
a pagar de los consumidores de zapatillas en Bogotá. Para lograrlo se aplicó un
experimento en el que se aplicó la metodología de Modelo de Elección Discreta MED,
dado que este método permite cuantificar tanto la intensión de compra como la
disposición a pagar por unos determinados atributos, en este caso las acciones de
responsabilidad social, y comparar los resultados con los obtenidos en el mismo
experimento por atributos de Competencias Corporativas. El experimento aplicado a 120
consumidores de ambos géneros, de diferentes estratos socioeconómicos y de diversas
edades, aporta evidencia empírica de la significativa relación positiva que existe entre la
Responsabilidad Social Empresarial y el comportamiento de compra de los individuos de
la muestra y de que el efecto producido por esos atributos de Responsabilidad Social en la
decisión de compra y en la disposición a pagar de los consumidores de zapatillas en
Bogotá, es más determinante que el producido por las Competencias CorporativasTesi
Non-Invasive Approach to Investigate the Mineralogy and Production Technology of the Mosaic Tesserae from the Roman Domus of Villa San Pancrazio (Taormina, Italy)
The archaeological excavations at Villa San Pancrazio (Taormina, Italy) are bringing to light a vast Roman-Imperial residential quarter featuring luxurious dwellings decorated with wall paintings and mosaic floors, pointing it out as one of the most significant archaeological sites of the city. The polychrome and black and white mosaics recovered date back to the middle Imperial period, during the 2nd century AD. This work deals with the first archaeometric investigations of the materials employed for the tesserae production with the aim of elucidating the mineralogical composition and obtaining analytical evidence that can contribute to extracting information related to their production technology. For that purpose, a non-invasive methodology, based on micro energy dispersive X-ray fluorescence (μ-EDXRF) spectrometry and Raman spectroscopy, was used to characterize a wide selection of stone, ceramic and glass tesserae. Chemometric tools were exploited to manage the large set of elemental data collected on black and white lithic samples, providing essential clues for the subsequent investigations. The results evidenced the employment of natural lithotypes (calcareous sedimentary, dolomitic and volcanic) local and imported, and also artificial materials, such as ceramic made firing magnesium-rich clays, soda-lime-silica glasses made with different opacifying and coloring agents (such as calcium antimoniate, cobalt and copper)This work was supported by project IT-742-13 for Consolidated Research Groups, funded by the Basque Country Government. P. Irizar gratefully acknowledges his predoctoral grant (PRE2018-085888) from the MINECO Spanish Ministry. O. Gómez-Laserna is grateful to the University of the Basque Country (UPV/EHU) for her postdoctoral contract. P. Cardiano also thanks University of Messina (FFABR UNIME 2020) for funding
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