Colour changes by laser irradiation of reddish building limestones

We have used X-ray photoelectron spectroscopy (XPS) as a novel method to investigate the causes of colour changes in a reddish limestone under irradiation by a Q-switched Nd:YAG 1064 nm laser. We irradiated clean dry and wet surfaces of Pidramuelle Roja, a building stone frequently used in the Asturian heritage, at fluences ranging from 0.12 to 1.47 J cm−2. We measured the colour coordinates and undertook XPS analysis of the state of oxidation of iron both before and after irradiation. Visible colour changes and potential aesthetic damage occurred on dry surfaces from a fluence of 0.31 J cm−2, with the stone showing a greening effect and very intense darkening. The colour change on dry surfaces was considerably higher than on wet surfaces, which at the highest fluence (1.47 J cm−2) was also above the human visual detection threshold. The use of XPS demonstrated that the change in colour (chroma and hue) is associated with a reduction in the iron oxidation state on dry surfaces during laser irradiation. This points out to a potential routinary use of XPS to analyse causes of colour changes during laser cleaning in other types of coloured building stones

Hydrochemical models of calcareous tuffs: A review

Los depósitos tobáceos en aguas dulces están ampliamente representados en la Península Ibérica, la mayoría de ellos relacionados con surgencias de acuíferos carbonáticos. Una gran parte de los modelos geoquímicos de la hidroquímica de las aguas en las que se generan dichos depósitos, se basan en suponer que el agua meteórica, previamente enriquecida en CO2 por la existencia de actividad microbiológica en el suelo, fluye a través de la porosidad y de las fracturas de un acuífero de calizo. El agua resultante tiene una naturaleza bicarbonatada cálcica. El reequilibrio con la pCO2 atmosférica después de la surgencia, por agitación del agua, o por acción metabólica de microorganismos fotosintéticos, da lugar a una amplia variedad de facies de tobas calcáreas. Sin embargo, la modelización hidrogeoquímica no ha sido completamente tratada y las condiciones geológicas del entorno no han sido consideradas en sistemas tobáceos generados en zonas de infiltración, en los que el suelo presenta bajas concentraciones de CO2 o cuando la naturaleza de las aguas no son bicarbonatadas cálcicas, sino Ca-Mg-SO4-HCO3. En este trabajo se muestran resultados hidrogeoquímicos de dos ejemplos muy importantes de sistemas tobáceos, actuales y fósiles: río Júcar (Valdeganga- Presa de la Central Hidroeléctrica del Bosque) y río Guadiana Alto (lagunas de Ruidera). Dichos resultados son comparados con otras surgencias kársticas estudiadas recientemente en áreas próximas. La naturaleza del agua del río Júcar y lagunas de Ruidera muestra unas facies hidroquímicas Ca-Mg-SO4-HCO3. Por lo tanto, la interpretación hidrogeoquímica no puede hacerse usando exclusivamente el sistema CO2–H2O– calcita, el cual por otra parte, ha sido utilizado eficazmente en estudios de tasas de precipitación en sistemas tobáceos, así como en la interpretación del registro paleoclimático de la tobas calcáreas, o en reacciones de karstificación de acuíferos calizos. En esta revisión evaluamos la influencia en la hidroquímica de las aguas de las reacciones de dedolomitización y la disolución del yeso en acuíferos dolomítico – yesíferos, las cuales son independientes de la presión parcial de CO2, así como la cinética y sostenibilidad del proceso en términos de génesis de sistemas tobáceos. También consideramos otras reacciones dependientes de CO2, tales como la calcificación del yeso y la disolución y precipitación de calcita por mezcla de aguas. Los modelos apuntados explican la naturaleza de las aguas de los acuíferos dolomítico - yesíferos, además de su gran potencial para generar sistemas tobáceos, poniendo en cuestión el argumento de suelos con horizontes húmicos bien desarrollados, no muy comunes en áreas áridas o semi-áridas. Finalmente, examinamos los efectos sobre el grado de saturación calcita y, por lo tanto, de su influencia en la formación de tobas de la mezcla de aguas procedente de acuíferos multicapa o compartimentados temporalmente.The calcareous tufa deposits in fresh waters are widely represented in the Iberian Peninsula, mostly related to springs from carbonate aquifers. Most studies on the geochemical modelling of the genesis of calcareous tufa consider the meteoric water percolating through the limestone aquifer is enriched in CO2 by existing microbiological activity in soil. The new equilibrium with atmospheric CO2 in springs and/or metabolic activity of microorganisms determines a rich variety of facies of calcareous tufa. The resulting water has a calcium bicarbonate nature. However, the hydrochemical modelling has not completely been addressed and the boundary conditions have not been taken into account in tufa systems in which soils present low CO2 concentrations or when the nature of waters are Ca-Mg-SO4-HCO3. In this paper, hydrochemical results from two important examples of genesis of calcareous tufa are presented: Júcar river (Valdeganga - Presa de la Central Hidroeléctrica del Bosque) and Guadiana Alto river (Ruidera pools). These results are also compared with other kart spring waters recently studied in the area. The water nature of Júcar river and Ruidera aquifers shows clearly a Ca-Mg-SO4-HCO3 facies. The hydrochemical interpretation cannot exclusively be explained using the CO2–H2O– calcite system, which has widely been used in studies of precipitation rates and paleoclimatic records of calcareous tufa or Karstification reactions of limestone aquifers. In this review, we evaluate the dedolomitization and gypsum dissolution, which are independent of partial pressure of CO2, and kinetics and sustainability of processes in terms of genesis of tufa systems. We also consider other CO2-dependent reactions such as the calcification gypsum and dissolution and precipitation of calcite by mixing waters. This explains the nature of waters from dolomite-gypsum aquifers and also their great generator potential of tufa systems, and refuses the interpretation based exclusively on the presence of humic acid-rich soils, not very common in arid and semi-arid areas. Finally, we examine mixing waters in multi-layered or compartmentalized seasonally aquifers, which can produce waters that develop calcareous tufa.Este trabajo se ha realizado en el marco del proyecto CGL2011-25162 del Ministerio de Economía y Competitividad

Modelización y estimación de la durabilidad de materiales pétreos porosos frente a la cristalización de sales

En la presente Tesis, se han evaluado los diferentes mecanismos por los que se produce la cristalización de sales y, cuantificado la durabilidad frente a la cristalización de rocas porosas, utilizadas ampliamente tanto en el patrimonio arquitectónico y cultural como en edificios actuales como material de construcción. Los mecanismos de cristalización de sales estudiados en la presente Tesis son tres: el proceso de evaporación de las salmueras en el interior de la roca; la influencia del sistema poroso en la secuencia de precipitación mineral; y, por último, la presión de cristalización que generan dichos minerales al crecer. Para cuantificar la durabilidad de estos mater iales se propone un ensayo de sales basado en ciclos de inmersión parcial. Para ello se evalúan diecinueve rocas porosas por sus diferentes características petrofísicas y petrográficas (principalmente rocas bioclásticas de diferente tamaño de grano); y se utilizan dos salmueras que se han seleccionado por su abundancia y agresividad: NaCl y Na2SO4. Finalmente, se propone un estimador teórico de durabilidad que incluye parámetros del sistema poroso y de las propiedades mecánicas de la roca.In this Thesis, different mechanisms of salt crystallisation are evaluated, and stone durability against salt crystallisation is also quantified. These stones are widely used not only in architectural and cultural heritage but also in modern buildings, used as building material. Three salt crystallisation mechanisms are studied: evaporation process of brines from porous media of rocks; the influence of porous media on the mineral precipitation sequence; and, finally, the crystallisation pressure that mineral growth produces over the pore wall. In order to quantify stone durability, a salt crystallisation test, based on partial immersion of the materials, is proposed. For this propose, nineteen porous stones have been chosen for their different petrophysical and petrographic characteristics (mainly bioclastic rocks with different grain size); and, two brines have been also used for their abundance and aggressiveness: NaCl and Na2SO4. Finally, a durability theoretic estimator is proposed, including parameters of porous media and mechanical properties of rocks

Rankings de Universidades Chilenas Según los Ingresos de sus Titulados

This paper ranks Chilean universities for a sample of careers, using income data of graduates some years into their professions. The concept of ranking is constrained to categories, namely first-, secondand third-class universities, so defined with respect to the average of all universities. For the estimations, a two-level model is used with graduates from the same career, level 1, and grouped by universities, level 2. Some conclusions can be drawn from the results. First, rank depends on the career choice. However, universities in the Santiago and Valparaíso regions seem to predominate, particularly the traditional (existing before the Reform of 1981 that boosted the creation of private colleges) and earlier established ones. Second, rankings are generally robust when considering different groups of graduates. However, some evidence exists in favor of a tradeoff between number and quality of professionals, and of the presence of a “signal” effect à la Spence.

"The co-sleeping, benefit or hurt the relationship?"

Estudio piloto fin de Máster, para valorar la posible problemática sobre la realización del colecho y frente los roces con la pareja y la lactancia materna, en la zona norte de Madrid. Tras valorar los datos no puedo decir, si realizar colecho es bueno o malo, todo depende de la formación, interés y de los responsables que sean los padres. Lo que sí puedo decir es que no es una decisión para tomar a la ligera, sin el consentimiento y acuerdo de ambas partes,debería de tomarse antes de tener los hijos, ya que no se debe obligar a nadie.Final pilot study of Master, in order to evaluate the possible problematic on the realization of the collection and the frictions with the couple and the breastfeeding, in the north zone of Madrid. After evaluating the data I can not say, if collecting is good or bad, it all depends on the training, interest and the responsible parents. What I can say is that it is not a decision to take lightly, without the consent and agreement of both parties, it should be taken before having the children, as it should not be forced on anyone

Healthy sexuality and gender violence. Educational innovation and update for sanitarians, teachers and students

El siguiente trabajo fin de máster en Formacion de Profesorado de Secundaria, presenta el panorama actual dentro del aula sobre el campo de Violencia de Género. Consta de dos partes la primera es una investigación sobre conocimientos y experiencias de los alumnos y la segunda una innovacion educativa de ampliacion de los temarios de Formación Profesional Sanitaria Téc en cuidados auxiliares de enfermería. Está innovación pretende atender está carencia encontrada en los temarios, pretendiendo una mejora asistencial como futuros profesionales y prepararles para su desarrolllo profesional.The following master's thesis in Secondary Teacher Training, presents the current panorama within the classroom on the field of Gender Violence. It consists of two parts, the first is an investigation of knowledge and experiences of the students and the second an educational innovation of expansion of the subjects of Vocational Health Health Training in auxiliary nursing care. This innovation seeks to address this lack found in the programs, seeking an improvement in care as future professionals and prepare them for their professional development

Experimental investigation of multiple industrial wastes for carbon dioxide removal strategies

Industrial solid waste by-products are being increasingly employed for geochemical carbon dioxide removal (CDR) strategies due to their fine grain size, accessibility, and large annual production tonnages. Here, a range of such by-products has been tested experimentally for their reactivities with CO2 and water. Sample solutions were monitored for 100 h for changes in chemistry, and solid samples were characterised pre- and post-experiment. Samples rich in Ca- and Mg-bearing minerals, such as dunite, kimberlite, and ilmenite mine tailings, as well as marble quarry cuttings, were key cation sources. Ni sulphide, fluorite and borax tailings, coal-fired power plant fly ashes, and red mud samples showed high dissolution rates. The highest reaction rates were often observed during the initial few hours, and compared well to rates determined for rocks typically targeted for CDR purposes, such as basalt and gabbro. Several samples also showed secondary carbonate precipitation, suggesting opportunities for the development of single-step CDR technologies. Overall, the results of this study indicate that several industrial by-products can provide sufficient cations at favourable dissolution rates for geochemical CDR purposes. Any on-site or near-site conditions for reaction acceleration such as heat, concentrated CO2 or microbes, could further increase favourability for geochemical CDR opportunities.LB and JLFT are funded under H2020-EU.1.3.2. (DETAILS Project, grant agreement ID: 101018312)

Estimation of the Radon Risk Under Different European Climates and Soil Textures

Radon is a radioactive gas produced from the natural radioactive decay of uranium and is found in almost all rocks and soils. In confined places (e.g., dwellings, workplaces, caves, and underground mines), radon may accumulate and become a substantial health risk since it is considered the second most important cause of lung cancer in many developed countries. Radon risk assessment commonly considers either field or estimate values of the radon concentration and the gas permeability of soils. However, radon risk assessment from single measurement surveys to radon potential largescale mapping is strongly sensitive to the soil texture variability and climate changes, and particularly, to the soil water content dynamic and its effect on soil gas permeability. In this paper, the gas permeability of soils, and thus, the estimation of radon risk, is studied considering the effect of three different climates following the Köppen classification and four soil textures on soil water content dynamics. This investigation considers the CLIGEN weather simulator to elaborate 100-year length climatic series; Rosseta 3 pedotransfer function to calculate soil hydraulics parameters, and the HYDRUS-1D software to model the dynamics of water content in the soil. Results reveal that climate strongly affects gas permeability of soils and they must be considered as an additional factor during the evaluation of radon exposure risk. The impact of climate and texture defines the soil water content dynamic. Coarse soils show smaller gas permeability variations and then radon risk, in this case, is less affected by the climate type. However, in clay soils, the effect of climate and the differences in soil water content derive in gas permeability variations between 100 and 1,000 times through an annual cycle. As a result, it may cross the boundary between two radon risk categories. Results deeply confirm that both climate and texture should be compulsory considered when calculating the radon exposure risk and in the definition of new strategies for the elaboration of more reliable geogenic radon potential largescale maps.This work was supported by the Spanish Ministry of Science, Innovation, and Universities [grant number RTI2018-099052-BI00] and Regional Governments of Comunidad Valenciana (Spain) [grant number AICO/2020/175]. A pre-doctoral research fellowship (PRE2019-088294) was awarded to SG-O for the project RTI2018-099052-BI00