El deterioro de las piedras graníticas de la fachada de la Catedral de Vila Real (N de Portugal)

The cathedral of Vila Real (North of Portugal) is located in the city centre and at least four regional two-mica granites were used in its construction. A petrographic study of these granites concluded that the stones had different degrees of alterations. The identification of some physical properties of the granites –open porosity, real and apparent density, free water absorption, porometry and capillary transmission– confirms their susceptibility to degrees of weathering. A recent cleaning intervention was made and several types of deterioration were visible in the monument‚s stones, namely: granular disintegration, some thin black layers, plates, flakes and black crusts, especially in the main front exposed to SW. Granular disintegration is the most important deterioration process and is responsible for the loss of material in the most-affected stones; it is also related to the presence of small amounts of highly soluble salts such as halite and nitrates and to solar exposure.La Catedral de Vila Real (Norte de Portugal) se encuentra en el centro de la ciudad y se han utilizado, al menos, cuatro granitos de dos micas para su construcción extraídos de sus alrededores. El estudio petrográfico de estos granitos pone de manifiesto que poseen un diferente grado de alteración. La determinación de algunas propiedades físicas de los granitos –porosidad abierta, densidad aparente y real, absorción libre de agua, porometría y capilaridad– confirman los distintos grados de alteración. La catedral ha sufrido una reciente limpieza y sobre las piedras de la Catedral se observan distintas formas de alteración, sobre todo desagregación granular (arenización), escasas pátinas finas negras, desplacaciones, escamas y costras negras, especialmente en la fachada principal, expuesta al SW. El fenómeno de la desagregación granular es el más importante y es el responsable de de la pérdida de material en las piedras más afectadas. Su génesis se relaciona con la presencia de pequeñas cantidades de sales solubles, como halita y nitratos, y a la exposición al sol

Aplicación de la microscopía óptica de fluorescencia al estudio textural del clínker de cemento portland

The application of fluorescence light microscopy in the textural study of Portland cement clinker, specially its porosity, is presented. Principles and types of the technique are commented and the suggested sample preparation method is described. The use of fluorescence microscopy allows an easier study of the clinker porosity, and very proper images for automated quantification can be obtained. Besides, the samples can also be observed by reflected-light polarizing microscopy.Se presenta la utilidad de la microscopía óptica de fluorescencia para el estudio textural del clínker de cemento Portland, especialmente su porosidad. Se comentan los fundamentos y modalidades de la técnica, y se describe el método recomendado de preparación de muestras. La utilización de la microscopía de fluorescencia permite un estudio más fácil de la porosidad, obteniéndose imágenes muy apropiadas para su cuantificación mediante técnicas automatizadas. Además, las muestras para fluorescencia pueden ser estudiadas complementariamente por microscopía óptica de polarización por luz reflejada

Características tecnológicas de las rocas ornamentales de Asturias

Las ocho explotaciones de rocas omamentales existentes en Asturias a comienzos de 2000 aprovechaban dos formaciones geológicas paleozoicas (Amao y Alba) y una mesozoica (Lastres). En las dos primeras se extraian calizas, mientras que en la tercera se explotaban areniscas.Aqui se presentan las caracteristicas petrograficas (textura, mineralogia, etc.) y fisico-mecánicas (densidad, porosidad, absorción de agua, heladicidad, resistencias a la cnstalizaci6n de sales,al choque, al desgaste, a la compresion uniaxial y a la flexión) de dichos niateriales, con el fin de darlas a conocer en el sector de la Piedra Natural (no aparecen en los catálogos de rocas ornamentales españolas) y facilitar información respecto a su utilización más idónea. En base a los resultados obtenidos, las calizas, como roca ornamental, podrian ser utilizadas para cualquier fin, mientras que las areniscas podrian presentar, a largo plazo, algunas limitaciones en ambientes marinos y/o contaminados.At the beginning of 2000, eight ornamental stone quarries in Asturias extracted rocks from two paleozoic formations (Amao and Alba) and a mesozoic one (Lastres). Limestones were exploited iii ihe two tirst formations, whereiis sdndstoties wem extracted from the third one. The petrographical (texrure, mineralogy, etc.) and physico-mechanical characteristics (volumetric weight, porosity, water absorptioii, frcczing and sal1 crystallization resisrance, elastic modulus, friction wear resistance, and impact, uniaxial compression and flexure strengths) of these materials are hcre presentcd, to introduce thcm to the Natural Stone sector (these rocks do not appear in the spanish ornamental stone catalogues) and to give infomation about their more suitable uses. Accvrding to the obtained results, limestones, as ornamental stone, could be used for any purpose, while sandstones could have, after long time, some probleins in marine andior contaminated environments

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Gamificación en Iberoamérica. Experiencias desde la comunicación y la educación

La presente obra capitular es el resultado de las investigaciones sobre las aplicaciones de la gamificación en contextos múltiples, emergentes provenientes de las comunicaciones presentadas en el Simposio 06 del III Congreso Internacional Comunicación y Pensamiento (Sevilla, España), así como de aquellas presentadas por los miembros del Gamelab UPS, del Proyecto I+D+i Coordinado “Competencias mediáticas de la ciudadanía en medios digitales emergentes (smartphones y tablets): Prácticas innovadoras y estrategias educomunicativas en contextos múltiples” (EDU2015-64015-C3-1-R) (MINECO/FEDER), de la “Red de Educación Mediática” del Programa Estatal de Investigación Científica-Técnica de Excelencia, Subprograma Estatal de Generación de Conocimiento (EDU2016-81772-REDT), financiados por el Fondo Europeo de Desarrollo Regional (FEDER) y Ministerio de Economía y Competitividad de España. En este sentido se busca construir, desde una mirada dual desde Europa y América Latina el primer libro iberoamericano de gamificación, avalado por el Gamelab de la Universidad Politécnica Salesiana (Ecuador), el Proyecto I+D+i EDU2015-64015-C3-1-R, la Red Interuniversitaria Euroamericana de Investigación sobre Competencias Mediáticas para la Ciudadanía (Alfamed), el Laboratorio de Estudios en Comunicación (Ladecom) y el Grupo de Investigación Ágora (PAI-HUM-648) de la Universidad de Huelva (España) y el Grupo de Investigación Estructura, Historia y Contenidos de la Comunicación GREHCCO

A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality

The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (X$_{max}$) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of X$_{max}$ with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy

Study on multi-ELVES in the Pierre Auger Observatory

Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity