CorTen steel: a solution to atmospheric degradation in acid and marine environments

35 p.: il.[EN] Weathering steel has a special resistance against the atmospheric corrosion through the formation of a protective layer. This layer is formed, among others, due to the reaction of some alloy elements present in the steel with reactive species, such as sulphur and nitrogen oxides and/or chlorides, which are present in the environment. For that reason, it is a widely used material in outdoor structures (facades, bridges) and it is in vogue among modern sculptors because this material changes its texture and colour with the pass of time and with the environment in which is exhibited. However, depending on the location, some problems could appear in the development of the protective layer. For instance, even if the acid gases collaborate in the formation of the rust layer, when they appear in high concentration they can be counter-productive in the well development of the protective layer. In fact, acid rain and marine aerosol can accelerate the corrosion process causing the leaching of some steel alloy metals. In consequence, the corrosion can be the responsible of the destruction of the structure, and moreover, the responsible of several negative enviromental impacts due to the toxicity of those leached metals. In this work spectroscopic techniques were used in order to determine the composition of protective layer, both the original composition and the degradation compounds formed due to the reaction of the material with the surrounding atmosphere. On the other hand, quantitative techniques, as well as monitoring the quantity of leached metals, they were helped in the development of a solution for the damage caused by chlorides and acid gases, being sulphates the most worrying stressors. For that purpose a ion exchange resin was employed with the aim of removing sulphates, chlorides and nitrates, and thus, avoiding the destruction of the steel structure.[EN] El acero de intemperie tiene una resistencia especial contra la corrosión atmosférica a través de la formación de una capa protectora. Esta capa se forma, entre otras cosas, debido a la reacción de algunos elementos de aleación presentes en el acero con especies reactivas, tales como óxidos de azufre y nitrógeno y/o cloruros, que están presentes en el medio ambiente. Por ello, es un material muy utilizado en estructuras exteriores (fachadas, puentes) y está de moda entre los escultores modernos porque este material cambia de textura y color con el paso del tiempo y con el entorno en el que se expone. Sin embargo, dependiendo de la ubicación, pueden aparecer algunos problemas en el desarrollo de la capa protectora. Por ejemplo, incluso si los gases ácidos colaboran en la formación de la capa de óxido, cuando aparecen en alta concentración pueden ser contraproducentes en el desarrollo de la capa protectora. De hecho, la lluvia ácida y el aerosol marino pueden acelerar el proceso de corrosión causando la lixiviación de algunos metales de aleación de acero. En consecuencia, la corrosión puede ser la responsable de la destrucción de la estructura, y además, la responsable de varios impactos ambientales negativos debido a la toxicidad de los metales lixiviados. En este trabajo se utilizaron técnicas espectroscópicas para determinar la composición de la capa protectora, tanto la composición original como los compuestos de degradación formados debido a la reacción del material con la atmósfera circundante. Por otro lado, las técnicas cuantitativas, además de monitorear la cantidad de metales lixiviados, ayudaron en el desarrollo de una solución para los daños causados por los cloruros y gases ácidos, siendo los sulfatos los estresantes más preocupantes. Para ello se empleó una resina de intercambio iónico con el objetivo de eliminar sulfatos, cloruros y nitratos, evitando así la destrucción de la estructura de acero

Understanding Mars through the Earth: Geochemical characterization of submarine volcano scenarios to be used as Martian analogues.

211 p.NASA and ESA will carry out their own planetary missions (Mars 2020 and ExoMars 2022 respectively) whose main objective is the demonstration of the potential habitability of the neighbouring planet. In this sense, all the findings that evidence the possibility of any life signature in the Martian history could be very interesting to fulfil this objective. With this purpose, the present PhD thesis is based in the geochemical characterization of different emplacements from the Basque-Cantabrian Basin, which are proposed as Martian analogues. All the studied locations are antique submarine volcano scenarios which have been subjected to different weathering processes since their eruption till nowadays. This characterization was done with spectroscopic techniques, among others Raman and visible near infrared spectroscopies, since they are on-board the mentioned missions. Therefore the use of these techniques in analogue emplacements could serve as a background for the Martian exploration. An example of one of the most common compounds found in these emplacements, are phyllosilicates. They play a very important role for the existence of life due to the necessity of water for their formation as well as sulfates and carbonates. Some of the found minerals in these emplacements have been already found on Mars but others, are not reported to be present in its surface yet and therefore their spectroscopic characterization will help in the interpretation of the upcoming results from the future missions. Moreover, some signals of organic molecules could also be identified in the analogue samples. Thanks to that, and due to the difficulty of the detection and interpretation of organic molecules, we have a spectroscopic background, and as in the case of the unknown minerals the understanding of the future data, would be easier

CorTen steel: a solution to atmospheric degradation in acid and marine environments

35 p.: il.[EN] Weathering steel has a special resistance against the atmospheric corrosion through the formation of a protective layer. This layer is formed, among others, due to the reaction of some alloy elements present in the steel with reactive species, such as sulphur and nitrogen oxides and/or chlorides, which are present in the environment. For that reason, it is a widely used material in outdoor structures (facades, bridges) and it is in vogue among modern sculptors because this material changes its texture and colour with the pass of time and with the environment in which is exhibited. However, depending on the location, some problems could appear in the development of the protective layer. For instance, even if the acid gases collaborate in the formation of the rust layer, when they appear in high concentration they can be counter-productive in the well development of the protective layer. In fact, acid rain and marine aerosol can accelerate the corrosion process causing the leaching of some steel alloy metals. In consequence, the corrosion can be the responsible of the destruction of the structure, and moreover, the responsible of several negative enviromental impacts due to the toxicity of those leached metals. In this work spectroscopic techniques were used in order to determine the composition of protective layer, both the original composition and the degradation compounds formed due to the reaction of the material with the surrounding atmosphere. On the other hand, quantitative techniques, as well as monitoring the quantity of leached metals, they were helped in the development of a solution for the damage caused by chlorides and acid gases, being sulphates the most worrying stressors. For that purpose a ion exchange resin was employed with the aim of removing sulphates, chlorides and nitrates, and thus, avoiding the destruction of the steel structure.[EN] El acero de intemperie tiene una resistencia especial contra la corrosión atmosférica a través de la formación de una capa protectora. Esta capa se forma, entre otras cosas, debido a la reacción de algunos elementos de aleación presentes en el acero con especies reactivas, tales como óxidos de azufre y nitrógeno y/o cloruros, que están presentes en el medio ambiente. Por ello, es un material muy utilizado en estructuras exteriores (fachadas, puentes) y está de moda entre los escultores modernos porque este material cambia de textura y color con el paso del tiempo y con el entorno en el que se expone. Sin embargo, dependiendo de la ubicación, pueden aparecer algunos problemas en el desarrollo de la capa protectora. Por ejemplo, incluso si los gases ácidos colaboran en la formación de la capa de óxido, cuando aparecen en alta concentración pueden ser contraproducentes en el desarrollo de la capa protectora. De hecho, la lluvia ácida y el aerosol marino pueden acelerar el proceso de corrosión causando la lixiviación de algunos metales de aleación de acero. En consecuencia, la corrosión puede ser la responsable de la destrucción de la estructura, y además, la responsable de varios impactos ambientales negativos debido a la toxicidad de los metales lixiviados. En este trabajo se utilizaron técnicas espectroscópicas para determinar la composición de la capa protectora, tanto la composición original como los compuestos de degradación formados debido a la reacción del material con la atmósfera circundante. Por otro lado, las técnicas cuantitativas, además de monitorear la cantidad de metales lixiviados, ayudaron en el desarrollo de una solución para los daños causados por los cloruros y gases ácidos, siendo los sulfatos los estresantes más preocupantes. Para ello se empleó una resina de intercambio iónico con el objetivo de eliminar sulfatos, cloruros y nitratos, evitando así la destrucción de la estructura de acero

APRENDER QUÍMICA DE NIVEL UNIVERSITARIO CON EL USO DE AULA INVERTIDA EN DOCENCIA A DISTANCIA

Durante el curso 2020/2021 en un contexto de docencia a distancia provocado por la pandemia por COVID-19, implantamos la metodología de aula invertida en dos temas de la asignatura de Química del Grado de Ingeniería Agroambiental. La misma asignatura fue impartida en su totalidad con metodología de clase magistral online en el Grado de Ingeniería Agrícola. Los resultados muestran que el aula invertida condujo a una menor procrastinación, aumentando los estudiantes que siguen la asignatura y realizan las actividades de clase. Sin embargo, en estas condiciones de docencia a distancia, se observó una alta tasa de absentismo, independientemente de la metodología docente. Aunque no se observan diferencias en las calificaciones entre metodologías, el aula invertida ha resultado satisfactoria, proponiéndose ampliar su uso en cursos posteriores, tras realizar las mejoras pertinentes

El aula invertida para la docencia de Física

En este trabajo presentamos una experiencia docente on-line con estudiantes universitarios de primer curso basada en la aplicación del aula invertida para el estudio de cinemática de sólido rígido. Los resultados del estudio no demuestran diferencias significativas con respecto a otros temas tratados ni con respecto al mismo tema en el curso anterior, en el que la docencia no fue virtual sino presencial

ExoMars Raman Laser Spectrometer RLS, a tool for the potential recognition of wet target craters on Mars

In the present work, NIR, LIBS, Raman and XRD techniques have been complementarily used to carry out a comprehensive characterization of a terrestrial analogue selected from the Chesapeake Bay Impact Structure (CBIS). The obtained data clearly highlight the key role of Raman spectroscopy in the detection of minor and trace compounds, through which inferences about geological processes occurred in the CBIS can be extrapolated. Beside the use of commercial systems, further Raman analyses were performed by the Raman Laser Spectrometer (RLS) ExoMars Simulator. This instrument represents the most reliable tool to effectively predict the scientific capabilities of the ExoMars/Raman system that will be deployed on Mars in 2021. By emulating the analytical procedures and operational restrictions established by the ExoMars mission rover design, it was proved that the RLS ExoMars Simulator is able to detect the amorphization of quartz, which constitutes an analytical clue of the impact origin of craters. On the other hand, the detection of barite and siderite, compounds crystallizing under hydrothermal conditions, helps to indirectly confirm the presence of water in impact targets. Furthermore, the RLS ExoMars Simulator capability of performing smart molecular mappings was also evaluated. According to the obtained results, the algorithms developed for its operation provide a great analytical advantage over most of the automatic analysis systems employed by commercial Raman instruments, encouraging its application for many additional scientific and commercial purposes

ExoMars Raman Laser Spectrometer: A Tool for the Potential Recognition of Wet-Target Craters on Mars

In the present work, NIR, LIBS, Raman and XRD techniques have been complementarily used to carry out a comprehensive characterization of a terrestrial analogue selected from the Chesapeake Bay Impact Structure (CBIS). The obtained data clearly highlight the key role of Raman spectroscopy in the detection of minor and trace compounds, through which inferences about geological processes occurred in the CBIS can be extrapolated. Beside the use of commercial systems, further Raman analyses were performed by the Raman Laser Spectrometer (RLS) ExoMars Simulator. This instrument representsthe most reliable tool to effectively predict the scientific capabilities of the ExoMars/Raman system that will be deployed on Mars in 2021. By emulating the analytical procedures and operational restrictions established by the ExoMars mission rover design, it was proved that the RLS ExoMars Simulator is able to detect the amorphization of quartz, which constitutes an analytical clue of the impact origin of craters. On the other hand, the detection of barite and siderite, compounds crystallizing under hydrothermal conditions, helps to indirectly confirm the presence of water in impact targets. Furthermore, the RLS ExoMars Simulator capability of performing smart molecular mappings was also evaluated. According to the obtained results, the algorithms developed for its operation provide a great analytical advantage over most of the automatic analysis systems employed by commercial Raman instruments, encouraging its application for many additional scientific and commercial purposes.Proyecto MINECO Retos de la Sociedad. Ref. ESP2017-87690-C3-1-

Design of remediation pilot plants for the treatment of industrial metal-bearing effluents (BIOMETAL DEMO project): Lab tests

Current research is the first part of the BIOMETAL DEMO project, funded by the European Union, focusing on the development of complementary and modular biotreatment processes for the removal of metal ions from industrial effluents (issued from mining industry, surface treatment and ceramics). Metal bio-precipitation (in form of metal sulfides and metal phosphates) using sulfate-reducing bacteria (SRB), phytase and phosphatase enzymes, biosorption using sugar-beet pulp, algal biomass and alginate- or chitosan-based composites (immobilizing polyethyleneimine derivatives by encapsulation) have been extensively studied using synthetic and industrial effluents. These preliminary results allow designing a treatment flow-sheet including pre-treatment of the effluent using biologically-assisted precipitation followed by biosorption (for mining effluents that contain sulfate anions). For surface treatment and ceramics effluents, bio-precipitation combined with biosorption processes and physicochemical pretreatment followed by biosorption process represent, respectively, a promising solution. The carbon-source for the SRB process, the optimization of process parameters and the biosorbents have been selected taking into account both the technical performance and the economic viability.European Union's Seventh Framework ProgrammeDepto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasTRUEpu

Study of a Terrestial Martian Analogue: Geochemical Characterization of the Meñakoz Outcrops (Biscay, Spain)

Collection of the raw Raman and NIR spectral dat