Reduction of wood hygroscopicity and associated dimensional response by repeated humidity cycles

The reduction of wood response to variations of ambient humidity, described as kind of ageing, has been studied from both points of view of moisture uptake and dimensional changes. Clearwood specimens from 3 gymnosperms (Pinus sylvestris L., Pinus pinaster Ait., Pinus insignis Dougl.) and 4 angiosperms (Populus spp., Quercus pyrenaica Willd., Entandrophragma cylindricum Sprague, Chlorophora excelsa Benth. & Hook f.) were subjected to five wet-dry cycles and their moisture content and dimensional changes in radial and tangential direction at three increasing levels of relative humidity (57.6, 84.2 and 90.2%) were measured before and after the treatment. For a given increase of relative humidity, a coefficient of hygroscopic ageing was defined as the relative decrease of moisture uptake, and the coefficient of dimensional ageing as the difference of swelling strain before and after ageing. All species exhibited a clear ageing effect, much stronger in the wet range than in the dry range. Calculation of swelling coefficients suggested that in some cases the relation between swelling strain and moisture content is no longer linear in aged wood.Comment: to be published in Annals of Forest Scienc

Prediction of standard particleboard mechanical properties utilizing an artificial neural network and subsequent comparison with a multivariate regression model

The physical properties (specific gravity, moisture content, thickness swelling and water absorption) and mechanical properties (internal bond strength, bending strength and modulus of elasticity) were determined on 93 Spanish-manufactured standard particleboards of different thicknesses selected randomly at the end of the production process. The testing methods of the corresponding European standards (EN) were used, except in the case of the thickness swelling and absorption tests, for which the Spanish UNE standard was used. The thickness and the values obtained for the physical properties were entered into an artificial neural network in order to predict the mechanical properties of the board. The fit was compared with the usual multivariate regression models. The use of a neural network made it possible to obtain the values of bending strength, modulus of elasticity and internal bond strength of the boards utilizing the known data, not only of thickness, moisture content and specific gravity, but also of thickness swelling and water absorption. The neural network proposed is much better adapted to the observed values than any of the multivariate regression models obtained

Variation throughout the tree stem in the physical-mechanical properties of the wood of Abies alba Mill. from the Spanish Pyrenees

This study analyses the variation of main physical-mechanical properties of wood along the longitudinal and radial directions of the tree for Abies alba Mill. growing in the Spanish Pyrenees. Small clear specimens were used to study the properties of volumetric shrinkage (VS), density (?), hardness (H), bending strength (MOR), modulus of elasticity (MOE), maximum compressive strength parallel to the grain (MCS) and impact strength (K). Several models of properties variation in the longitudinal and radial directions were analyzed. Main trends of variation of properties throughout the tree stem were identified although none of them could be fitted to predictive statistical models. Along the longitudinal direction, the properties studied followed a downward trend from the base to the crown, which was not significant in all cases, indicating that no differences in quality existed. Throughout the radial direction the trend is upward for the first 40-50 growth rings, after which it slopes downwards, more gently at first until rings 70-75 and then more steeply. This behaviour is related to variation in wood structure from the pith to the bark, depending on whether the wood is juvenile, sapwood or heartwood, and to wood maturity and microfibril angle. Authors encourage carrying further studies on other populations of A. alba in the Spanish Pyrenees to check if the trends found in this study apply to other provenances

Obtención del módulo de elasticidad estático de la madera de Pinus radiata D. Don. mediante la comparación de técnicas de regresión y una red neuronal artificial

El objetivo de este estudio ha sido comparar el método de regresión tradicional frente al diseño de una red neuronal artificial del tipo perceptrón multicapa para obtener el MOEestático de la madera de Pinus radiata D. Don. a partir del MOEdinámico obtenido por técnica de ultrasonidos en el primer caso y a partir de la velocidad de propagación de la onda de ultrasonidos en el segundo

Computer vision-based wood identification: a review

Wood identification is an important tool in many areas, from biology to cultural heritage. In the fight against illegal logging, it has a more necessary and impactful application. Identifying a wood sample to genus or species level is difficult, expensive and time-consuming, even when using the most recent methods, resulting in a growing need for a readily accessible and field-applicable method for scientific wood identification. Providing fast results and ease of use, computer vision-based technology is an economically accessible option currently applied to meet the demand for automated wood identification. However, despite the promising characteristics and accurate results of this method, it remains a niche research area in wood sciences and is little known in other fields of application such as cultural heritage. To share the results and applicability of computer vision-based wood identification, this paper reviews the most frequently cited and relevant published research based on computer vision and machine learning techniques, aiming to facilitate and promote the use of this technology in research and encourage its application among end-users who need quick and reliable results.info:eu-repo/semantics/publishedVersio

Use of Artificial Neural Networks as a Predictive Method to Determine Moisture Resistance of Particle and Fiber Boards Under Cyclic Testing Conditions (UNE-EN 321)

Determining internal bond strength and thickness swelling after cyclic aging tests in humid conditions is essential to assess moisture resistance of particle and fiber boards. However, because operating procedures for these types of tests take at least 3 wk, their use in daily finished product control is impractical. To solve this problem, an artificial neural network was used as a predictive method to determine these values from the board properties of thickness, density, and moisture content in conjunction with thickness swelling and internal bond strength values obtained before the aging cycle. Using 113 boards, an artificial neural network was designed consisting of two separate feedforward multilayer perceptrons applying the hyperbolic tangent as the transfer function. Training was conducted through supervised learning after the input data had been normalized. In the testing group, the network attained a determination coefficient of 0.94 for internal bond strength and 0.92 for thickness swelling

Aplicación metodología cualitativa para el estudio del impacto de la pandemia COVID-19 en titulaciones de Ciencias de la Salud, Terapia Ocupacional y Fisioterapia

[EN] The COVID-19 pandemic forced a sudden adaptation of higher education to a complex and changing reality, by incorporating new technologies for teaching. The Health Sciences degrees have adapted their curriculum to this new reality, where the teaching and learning process has been modified by incorporating new technologies, distance learning and limitation of clinical practices in health centers. It is necessary to analyze dimensions such as the teaching and learning process, the modification of the material used, the integration of theoretical and practical content, and the participation of students in the development of educational material. The objective of this work is to present 6 qualitative research proposals that help to understand the adaptation of professors and students to this new reality, together with the teaching and learning process and the incorporation of new tools and teaching methods (e-learning) during the pandemic.[ES] La educación superior ha precisado adaptarse a una nueva realidad compleja debido a la pandemia del COVID-19. Esto ha obligado incorporar nuevas tecnologías para la enseñanza superior. Como consecuencia, las titulaciones universitarias, como las de las ciencias de la salud, han ido realizando modificaciones y adaptándose incorporando nuevas tecnologías y metodología de enseñanza. Pero existen dimensiones como las prácticas clínicas en centros sanitarios que siguen planteando retos dentro del proceso de enseñanza y aprendizaje en estas titulaciones. Es preciso analizar en Ciencias de la Salud, dimensiones como el proceso de enseñanza y aprendizaje, la modificación del material docente utilizado, la integración de los contenidos teóricos y prácticos, y la participación de los estudiantes en el desarrollo de material docente. El objetivo de esta comunicación es presentar 6 propuestas de investigación cualitativa, que ayuden a desarrollar y elaborar estudios que analicen y profundicen en la perspectiva de los profesores y estudiantes en esta nueva realidad, junto al proceso de enseñanza e incorporación de métodos de enseñanza (e-learning) durante la pandemia.Moro, P.; Palacios-Ceña, D.; Lima Florencio, L.; Perez Corrales, J.; Gueita Rodriguez, J.; Martinez Piedrola, R.; Perez De Heredia, M.... (2021). Aplicación metodología cualitativa para el estudio del impacto de la pandemia COVID-19 en titulaciones de Ciencias de la Salud, Terapia Ocupacional y Fisioterapia. En IN-RED 2021: VII Congreso de Innovación Edicativa y Docencia en Red. Editorial Universitat Politècnica de València. 970-982. https://doi.org/10.4995/INRED2021.2021.13743OCS97098

Política y libertad.

El debate sobre la libertad y la política es parte obligada del estudio del Centro de Pensamiento de la Universidad Sergio Arboleda. Según la concepción que al respecto se tenga se derivan diversas consecuencias en relación con el manejo y estructuración del Estado. La presente publicación contiene una serie de textos de diferentes personajes cuyo pensamiento aborda el marco político, social y económico sobre el cual deben articularse las libertades ciudadanas. Estimamos que la difusión de estas reflexiones contribuirá a la discusión, siempre fructífera, de las ideas y abrirá el camino para que otros autores planteen sus propios puntos de vista sobre estos temas

Extracellular vesicles from pristane-treated CD38-deficient mice express an antiinflammatory neutrophil protein signature, which reflects the mild lupus severity elicited in these mice

In CD38-deficient (Cd38-/-) mice intraperitoneal injection of pristane induces a lupus-like disease, which is milder than that induced in WT mice, showing significant differences in the inflammatory and autoimmune processes triggered by pristane. Extracellular vesicles (EV) are present in all body fluids. Shed by cells, their molecular make-up reflects that of their cell of origin and/or tissue pathological situation. The aim of this study was to analyze the protein composition, protein abundance, and functional clustering of EV released by peritoneal exudate cells (PECs) in the pristane experimental lupus model, to identify predictive or diagnostic biomarkers that might discriminate the autoimmune process in lupus from inflammatory reactions and/or normal physiological processes. In this study, thanks to an extensive proteomic analysis and powerful bioinformatics software, distinct EV subtypes were identified in the peritoneal exudates of pristane-treated mice: 1) small EV enriched in the tetraspanin CD63 and CD9, which are likely of exosomal origin; 2) small EV enriched in CD47 and CD9, which are also enriched in plasma-membrane, membrane-associated proteins, with an ectosomal origin; 3) small EV enriched in keratins, ECM proteins, complement/coagulation proteins, fibrin clot formation proteins, and endopetidase inhibitor proteins. This enrichment may have an inflammation-mediated mesothelial-tomesenchymal transition origin, representing a protein corona on the surface of peritoneal exudate EV; 4) HDL-enriched lipoprotein particles. Quantitative proteomic analysis allowed us to identify an anti-inflammatory, Annexin A1- enriched pro-resolving, neutrophil protein signature, which was more prominent in EV from pristane-treated Cd38-/- mice, and quantitative differences in the protein cargo of the ECM-enriched EV from Cd38-/- vs WT mice. These differences are likely to be related with the distinct inflammatory outcome shown by Cd38-/- vs WT mice in response to pristane treatment. Our results demonstrate the power of a hypothesis-free and data-driven approach to transform the heterogeneity of the peritoneal exudate EV from pristanetreated mice in valuable information about the relative proportion of different EV in a given sample and to identify potential protein markers specific for the different small EV subtypes, in particular those proteins defining EV involved in the resolution phase of chronic inflammation.Proyecto del plan estatal, Ministerio de Ciencia e Innovacion PT13/0001/011CSIC PT17/0019/0010 PID2020-119567RB-I0

Virtualizing university teaching through Open Educational Resources by means of ArcGIS Online (REARGOL)

La pandemia provocada por el virus SARS-CoV-2 (COVID19) ha demostrado la necesidad de acelerar la digitalización de la docencia universitaria. Las herramientas digitales para la transferencia ciencia-educación, que ya eran esenciales para asegurar la calidad de la docencia presencial, se han transformado en imprescindibles cuando las circunstancias han impuesto la docencia virtual. El proyecto REARGOL ha desarrollado y ensayado en ArcGIS online instrumentos para la virtualización de contenidos en asignaturas de grado y máster, sobre geomorfología, gestión de desastres, patrimonio natural y patrimonio cultural. Ha sido un ensayo piloto, replicable en todas las titulaciones y temáticas susceptibles de generar información geoespacial (prácticamente todos los títulos y áreas de conocimiento). El único límite es la imaginación. El proyecto ha priorizado la participación de estudiantes de grado, máster y doctorado, que han desarrollado 4 tipos de aplicaciones: Mapas Web y Web AppBuilder (visores cartográficos interactivos), encuestas Survey 123 (formularios recogida de datos), Cuadros de Mandos (plataformas online que permiten combinar varias aplicaciones) y Story Maps (presentaciones para mostrar conjuntamente información y aplicaciones ArcGIS online). Las aplicaciones que se ensayaron con éxito durante el curso 2020-2021, en asignaturas de grado y máster, así como en TFMs y TFGs, continúan utilizándose en el curso 2021-2022.The SARS-CoV-2 (COVID19) pandemic has shown the urgent need to improve university teaching. Digital resources for Science-Education transfer, which already were crucial for ensuring the quality of face-to-face teaching, turned to be indispensable when the health crisis forced virtual teaching. The REARGOL project has developed and tested ArcGIS Online tools for the virtualization of Bachelor’s and Master’s courses focused on geomorphology, natural disaster management, and natural and cultural heritage. This has been a preliminary test that could be applied to all undergraduate and postgraduate degrees, that can produce geospatial information in all knowledge areas. Imagination is the only constraint. The project has prioritized the participation of undergraduate and postgraduate students (Master and PhD). The project has priorized the participation of undergraduate and postgraduate (Master’s and PhD) students. They have developed four types of applications: Web Maps and Web AppBuilder (interactive cartographical viewers), Survey 123 (data collection forms), Dashboards (online platforms allowing to combine several applications) and Story Maps (presentations for displaying information and ArcGIS online applications). The tools successfully tested during the 2020-2021 academic year are still being used in the current one, in Bachelor’s and Master’s degrees, as well as in Bachelor’s and Master’s final dissertations.Depto. de GeografíaFac. de Geografía e HistoriaFALSEsubmitte